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Bread and Circuses (circumlunar version)

I don't often make exact predictions about the future; that's not an SF writer's job, and it's really easy to get egg on your face. Howver, here's a prediction:

If Donald Trump is still president, US astronauts will return to circumlunar space around July 16th, 2019 ...

That's the 50th anniversary of the launch of Apollo 11. It's also 6-12 months on from the projected date of Musk's translunar tourist trip on a Falcon Heavy.

I expect Falcon Heavy to be delayed a few months, minimum, because no new launch vehicle ever flies on time, especially a crew-rated one, but it's currently due to fly around December this year for the first time, with a vehicle currently undergoing integration at Cape Canaveral and commercial orders for subsequent flights. It's rather hard to describe it as vaporware at this point. The same goes for the Dragon 2 crewed capsule; it's due for a first uncrewed orbital flight test in March 2018, and a crewed orbital test flight later in 2018.

The combination of Dragon 2 and Falcon Heavy will be a vehicle roughly intermediate in payload between the Saturn IB and Saturn V—the cost of a Falcon Heavy launch with a flight profile that doesn't permit recovery of the stack is estimated at somewhere around $200-250M.

Now, I don't expect to see a human lunar landing in 2019. It'd require the development of a new lunar module, space suits, and a new mission profile and training in only two years. This is almost certainly impossible, not only for today's sclerotic NASA but also for SpaceX -- agile management will only get you so far. It'd also require at least two Falcon Heavy launches to put the stack in Lunar orbit—Falcon Heavy, even in non-reusable form, has a significantly smaller payload than Saturn V—at which point you're talking at least half a billion for the launchers with the R&D cost of the lander on top. However, a circumlunar flag-waving flight (sans lander) over the anniversary of Apollo 11 is entirely possible, using a mission profile SpaceX is apparently already developing for private customers with a target flight in late 2018.

I'm making this a prediction, however, because the POTUS factor.

July 2019 lies within the term in office of Donald Trump (or Mike Pence, depending whether impeachment/removal has happened first then). Trump is nothing if not an egomaniac, and offering him the opportunity to make a historic phone call to lunar orbit in front of the TV cameras is a guaranteed ego-stroke. Trump is of an age to have young-adult memories of Apollo and I can't see the idea not appealing to him if he can take credit for it.

So I'm betting that this is how Musk will fund development of his lunar-orbit capability.

(Terms and conditions: prediction invalid in event of nuclear war, global environmental or economic collapse, Trump and Pence both being impeached, or a Dragon 2 capsule exploding in flight, because any of these things might impact the launch schedule.)

445 Comments

1:

But, if DT is gone, as is entirely possible, if not likely ...
Why, then, would Pence even be interested - he's much more into bringing Jesus to the USA & sending all the women back to be good little breeders, like the arsehole just Primaried in Alabama .....

2:

(Rejoining the fray after 2 weeks in Japan...)

Very plausible prediction. The question is whether the anti-science faction in the U.S. manages to persuade the administration that the world is really flat, and that the moon landing really was faked--in which case, no mission. Implausible? When I think of the current situation in the U.S. with respect to science, I get the sense that word (implausible) does not mean what I think it means.

One quibble: It seems that the plans for the LEM are still available (https://www.hq.nasa.gov/alsj/alsj-LMdocs.html), unlike those for the Saturn V. Obviously, it's not a simple question of feeding those plans into a 3D printer, but it seems like rather than reinventing the tech from scratch, you could update the existing plans to use modern technology where doing so wouldn't require a complete redesign. Still a lot of testing and systems integration work required, but starting with a proven design should greatly shorten the production curve.

3:

I'll be interested to see what Elon says at the IAC this week. If we're going out on limbs, then I'll predict that the free-return lunar mission won't be done on a falcon heavy, but on the scaled down version of BFR that's been rumoured for months.

4:

Of course, if the launch this year goes poorly, it will become vaporware...

(sorry, couldn't resist)

5:

Since we're talking about technology predictions:

https://www.theguardian.com/business/2017/sep/27/easyjet-electric-planes-wright-electric-flights

So far, it doesn't match my prediction in a previous thread that electric passenger planes are viable on the Boston to Miami route (~3 hrs), but they're getting there.

https://www.travelmath.com/flying-time/from/Boston,+MA/to/Miami,+FL

6:

I know someone who works on power system R&D for those things. Long haul flights using a hybrid power system involving a single gas turbine generator and electric propulsion also looks promising as the simplified plumbing is apparently enough of a saving to make it worth the effort.

She tells me that some people are seriously looking at superconducting grids to get the power to the motors. Midair quenches could be very exciting.

7:

Is it possible that the Chinese will put a crew on the moon?

Officially this is to celebrate the 50 years Apollo anniversary and "the common spirit of humanity" but mostly to get back at the USA and rub The Donalds face in it about "who is the greatest, most shiniest, Now? Hahahahaaa"

It is possible The Golden Urang-Utan is re-elected:

https://wolfstreet.com/2017/09/18/defense-contractors-shares-700-billion-bill-acquisition-orbital-northrop/

Splurging absurd numbers on defence cronies is certainly one way to stay in business!

8:

The announced date for the SpaceX round the moon trip is also the 50th anniversary of Apollo 8. The timescale almost matches the Apollo programme, the first Saturn V flew on November 9th 1967 and Apollo 8 was the third Saturn V launch (and the first one manned) in December 1968.

Sometime I want to work out what the payload capability of an Apollo LEM style stage using a SpaceX Super Draco with a decent nozzle extension to up the ISP would be.

9:

I ran into a cartoon recently suggesting what a US President might do for shits and giggles.

The scary thing is that I'm not sure that this would be beyond DT.

10:
Still a lot of testing and systems integration work required, but starting with a proven design should greatly shorten the production curve.

Probably not all that much — the expertise needed to implement that design no longer exists in any one place; the requisite number of engineers would have to come up to speed, to a level of knowledge not much short of designing from scratch. Even many of the components and materials are simply not available, and the replacements would have to be recalculated and retested.

The design would be more of an inspiration than a blueprint.

11:

Re: '... the Chinese will put a crew on the moon?'

Was also thinking the Chinese with the following plot (knife) twist.

Russia has the only facility that regularly and reliably launches astronauts into space. If DT keeps being DT, Russia might decide that they'd rather do business with someone else and sign an exclusive and lucrative deal with China. So both of the US's rival super powers get to rub the US's face in the dirt on the 50th anniversary of the historic US moon landing.


12:

It is not going to happen. You are correct that Trump wants it: he asked NASA to change the inaugural flight of the SLS, scheduled for 2019, to include a crewed Orion, or to advance the second flight of the SLS, which was already planned to include a crewed Orion, from 2022 to 2019. NASA said no.

As for the possibility of using Falcon Heavy and Dragon 2 instead of SLS and Orion, that is not going to happen either, as Congress needs to cough up the dough for it, and they are never going to pay for a rocket that is not the SLS (aka Senate Launch System).

One thing that might be politically possible is to launch the SLS with a Dragon 2 instead of Orion. I don't know, however, whether it its technically possible to put the Dragon 2 on the SLS.

13:

Yeah, it's not really possible to launch the D2 with the SLS. D2's crew escape systems have been designed around escaping from a deflagrating liquid fueled booster. The solids on the SLS make for a much harsher environment if they let go, so they'd never meet Nasa's Loss of Crew targets.

15:

Even many of the components and materials are simply not available, and the replacements would have to be recalculated and retested. ... The design would be more of an inspiration than a blueprint.

You beat me to it. To be honest I suspect less than 1% of the standard parts used back when exist off the shelf today. Many 0%. Just like when NASA started building the big launcher they found that the actual knowledge of WHY decision were made in the Saturn V project is not really documented anywhere. A Similar thing happened in the 5 years after WWII as the armed forces tried to start building nuclear weapons without PHDs in labs doing the work. The notes were not really useful "as is" for the new folks to just start machining parts.

Inspiration is correct.

Plus the LEM is a part of a system. Non trivial parts of it's design has to do with the entire launch, extract, mate to the command module, etc...

16:

I am also going to voice my skepticism that a circumlunar flight is going to happen in 2019. It's far more likely to happen in 2020 or 2021. A test flight in March of next year followed by a human flight in 2018 is way too tight. Seeing as how much the Falcon Heavy test flight has been pushed back already, I'm not sure Musk can meet that.

Let's investigate the 2 main competing priorities:

1. Falcon 9 Block 5. That is expected to fly by the end of the year. I could see any delay in this version pushing back Falcon Heavy.

2. The launch rate. Musk generally overpromises how many satellites SpaceX launches each year. It could be that a commercial launch gets delayed for the maiden flight of the Falcon Heavy (especially since Musk doesn't focus solely on SpaceX's bottom line)? However, I could see pressure on him to prioritize the commercial flights. I will admit that this isn't a significant problem for him.

Will the Falcon Heavy and Dragon 2 even be human rated by NASA in time for a 2018 launch? I thought Musk had to demonstrate Max Q abort before that could happen? Plus, NASA may want a new demonstration of launchpad abort capabilities. That was done with the old Dragon, not the new one.

17:

But, if DT is gone, as is entirely possible, if not likely ... Why, then, would Pence even be interested

Interested or not if the money is already in the pipeline (appropriated) the inertia of the project will keep it going if the target isn't too far into the future.

Just turning off the lights and sending people home creates unemployment for too many people/voters.

18:

HOLY SHIT. I had never seen a solid-fuel rocket exploding. Forget Dragon 2's launch abort system surviving that, can *anything* survive that?

19:

That's why the Shuttle was such an all-around terrible idea, as implemented. (The Soviets got it right, or at least less wrong, with Buran, which used liquid-fuelled boosters instead.)

Dragon isn't designed to launch atop solids, so has some hope of survival.

More recently, I've been essays suggesting that a Saturn V abort on the pad was probably non-survivable by the astronauts: the S-IVB fireball would engulf the capsule or collapse the parachutes after they opened. (Three thousand tons of fuel on the pad mean you need to get a long way away, very fast indeed, to stand a chance of survival.)

On the flip side, Soyuz cosmonauts have survived both an abort from the pad when the launch vehicle went boom, and an abort at hypersonic speed when staging failed. So we know that launch escape systems can work.

20:

Re: '... money is already in the pipeline (appropriated)'

Consider who's at the center of this melodrama. Googling 'US diverted appropriated funds' pulls up enough mentions and dates to suggest that this is common practice. Sometimes diversions make sense because of unanticipated events (e.g., move money from ebola to zika research during the zika scare) and sometimes it's just politics.


The same is true regarding the number of employed affected. 'Too big too fail' is a mantra, not a prediction.

21:

Sabik noted: "the expertise needed to implement that design no longer exists in any one place; the requisite number of engineers would have to come up to speed, to a level of knowledge not much short of designing from scratch. Even many of the components and materials are simply not available, and the replacements would have to be recalculated and retested."

Good point. I suspect that some systems (e.g., radios, shock absorbers, batteries, materials) could be simply replaced by off-the-shelf parts, and that some of the old engineering problems have been solved with newer and more effective technologies. And we do have significantly better computer-aided design (e.g., rapid prototyping) and manufacturing tools than we used to, which would cut a chunk out of the development time. But other key components (e.g,. propulsion systems) would have to be redesigned from scratch. That might amount to the majority of the design problem, in which case the time savings would be small.

David L noted: "Plus the LEM is a part of a system."

Indeed, and I explicitly noted that there would be "a lot of testing and systems integration work required".

22:

You'll probably find out shortly as Pence is going to announce NASA's new policy at the Space Research Council meeting which happens in a few days.

One other note, the new NASA administrator is gungho for human spaceflight and plans to cut science/research/robot landers, so its not so far fetch that they will re-focus resources on SLS.

23:

Could we put Donald Trump on the moon? Please? ASAP. 2019 at the latest.

Advisors could surely present this to him as the perfect opportunity for him to project himself into the history books. Perhaps his image could be permanently painted on the surface of the moon to commemorate his flight. Tweeting from the moon! The mind boggles.

Return flight optional.

24:

I suspect that some systems (e.g., radios, shock absorbers, batteries, materials) could be simply replaced by off-the-shelf parts, and that some of the old engineering problems have been solved with newer and more effective technologies.

I really have my doubts. Apollo was a tightly designed system. Weight meant everything. It was way more important than costs in most cases. There were all kinds of one off things since they were putting widgets into places with restrictions that just didn't apply to the rest of the planet. Plus many times they were on the bleeding edge of tech and making things that it didn't mater that a switch costs $1000 as it was just important to "get it done".

You mention shock absorbers. How many off the shelf units can deal with the temperatures and vacuum of space without a huge certification effort? And on and on and on.

I think you're underestimating just how much "one off tech" made up Apollo.

25:

Indeed, and I explicitly noted that there would be "a lot of testing and systems integration work required".

That's the easy part. There are all kinds of dependencies here. Diameter of the Saturn upper stages determined a lot about the size and way the LEM unfolded. And the other way. How much to create a docking hatch that will mate up with the LEM design. Or to change the LEM design which leads to changes in LEM structure which leads to changes in LEM weight and balance which ....

26:

The circumlunar flight is being paid for by the two as yet unidentified but well-off passengers, Congress don't get to have a say in funding.

Also for 16: NASA man rating only applies to NASA flights, for a privately funded trip FAA experimental vehicle rules apply and they're basically "You've read and signed the disclaimer?".

27:

Thomas Kelly, Grumman's chief engineer on the LEM project wrote a book about his experiences building the thing that's well worth a read (Moon Lander: How We Developed the Apollo Lunar Module). He devotes a lot of time to the problems they had with plumbing and wiring within their weight budgets, and how many times that weight budget had to be increased. A lot of the structure was machined, then acid etched to reduce weight, which made everything really vulnerable to corrosion. The first engineering units leaked all over the floor when delivered to Nasa for testing.

We have somewhat better metallurgy and way better composites these days, but I'd agree that there'd be very few off-the-shelf components in a modern crewed lander.

28:

And how much work would it take to rewrite, and comprehensively test, the tight, fault-tolerant onboard flight software that Margaret Hamilton wrote for Apollo?

29:

The REALLY interesting one would be North Korea getting a manned mission there, if only on a one-way flight: "I die here for the Great Leader!"

30:

I think the odds are at least as good that the Russians will stop taking US astronauts to ISS, just to rub it into Trump's schnozz who's really in charge. By Apollo 11s anniversary it might be that the US no longer has the ability to put people in orbit, let alone to the moon.

31:

Naw. They'll just keep doubling the price every few missions.

32:

The North Korea comment and finding space rated shock absorbers got me thinking of a silly question. Why couldn't North Korea create an old school Orion Nuclear Pulse space craft, and how soon could they launch it?

I don't think the timeline is two years, but that may be more because of the number and size of the h-bombs they can build in a certain timeframe. The bigger the yield and the smaller the gadgets the easier it is to build the rest of the craft. Weight becomes much less of an issue as you increase yield. They are crazy enough to launch it over they're own country and damn the fallout. They couldn't really be stopped from doing it for the same tactical and strategic reasons they can't be stopped from making more bombs. They certainly have the engineering skills to build it. AND, it would be a massive military advantage over every country on the planet. No need to scoot over to the moon to count coup.

33:

Re: 'Donald Trump on the moon?'

Don't forget to pack his golf clubs, plus his iPhone for selfies and tweets. Hmmm ... wonder how much of a fight NASA would put up if shortly after launch their mobile phone budget was 'diverted'.

34:

> Why couldn't North Korea create an old school Orion Nuclear Pulse space craft, and how soon could they launch it?

It's old school vapourware (chemical explosive demonstrators not withstanding) with some *very* exciting failure modes. You need a very large number of small, efficient and reliable nukes to get a smooth ride.

35:

More to the point, North Korea is geographically compact. Ahem: almost exactly the same area as England, not including Wales or Scotland. The fallout plume is going to have to go somewhere, and none of the neighbors are terribly friendly at the best of times. About the least likely launch direction to trigger World War Three is east, across the Sea of Japan, and try to get the hell into Low Earth Orbit before crossing over Japan proper (and it's THAAD and Patriot batteries) ... but that drops a shitload of fallout all over the main fisheries that provide the NK populace with protein. South crosses South Korea (instant armageddon time), North crosses Russia, West crosses China ... nope, nobody is going to be too keen on taking a facefull of fission fragments for the Glory of the Dear Leader.

(Also, the sheer number of gadgets you need to pop to put even a small Orion into orbit is in the low double-digits, minimum; to do anything useful you'd need to put hundreds of bombs aboard the ship. And once it's in orbit, what's it good for? Remember, Kennedy shitcanned the first iteration of Orion to cross his desk in 1960 because it was basically a spacegoing nuclear-armed dreadnought; if NK launches such a ship, what is the likely payload?)

36:

Yes, exactly. The only credible use case is a Fithp invasion

37:

"Why couldn't North Korea create an old school Orion Nuclear Pulse space craft... They certainly have the engineering skills to build it."

This is a joke, right?

I reckon it'd be tough for even somewhere like the US to do it, let alone the architect who's in the Masons.

38:

to rewrite, and comprehensively test, the tight, fault-tolerant onboard flight software that Margaret Hamilton wrote

The good news is that we now have much better software proving systems available, to the point where there's a slightly-better-than-theoretical operating system available. So it would be possible to have software much larger and more complex than Apollo could do.

The bad news is that it would have to be done by China, as no-one else has the ability to build the chips. It's vaguely possible that the US TLAs could build the chips, hut only at the cost of sidelining their other development, and they would be reluctant to do that for a propaganda effort.

As David Brin keeps reminding us, the fact-based parts of the US government are under attack. The problem with rocket launches is that they're hard to conceal if they go wrong, and you only get one chance. That's way too high risk for Trump and I think he's smart enough to know it. They also have to be built by reality-based scientists, space missions can't get away with F35-style iterative enhancement to approach the previously promised baseline.

39:

Yeah, that's what I was afraid of. I think the only deal killer (no pun intended) for all this is the number and size of reliable gadgets they can make. How clean they can make them could also be a huge issue.

True, launching becomes hard and the only viable launch direction is East into the Sea of Japan. The prominate winds and jet stream blow to the East keeping most of the homeland clean. THAAD and Patriot defense systems would be nearly useless. A hit on the pusher plate would be like a bug bite, and just getting to any other part of the craft would mean flying through multiple nuclear explosions, and significantly outside of their designed flight profiles.

The best build for this would be to go as big as possible. Carriage of hundreds of less sophisticated (i.e. larger, less reliable) gadgets is a lot easier that way as is building it to support personnel in orbit.

Once in orbit, it basically become a mobile fort. Very hard to attack and can counter attack at leisure. They can deorbit bombs wherever they want and hold the world hostage. For a more thoughtful blackmail scenario, think about threatening communications and spy satellites.

Taking out NK then becomes useless. The ship can act as our nuclear submarines do, as a doomsday MAD deterant. Loosing there fisheries is less of an issue, because they can blackmail countries and private corporations to provide food and other resources.

The only other things that make this hard are the unknown difficulty in actually building it, and the resources and time needed to make it happen without interference. They would only get one chance at making it work too, so it would be a Hail Mary scenario to launch it. Perhaps holding it in reserve until it looked like they had lost any other leverage.

You have said to think of the future as made by bond villians after all. ¯\_(ツ)_/¯

40:

My first thought is "Well, at least even Trump has a silver lining". And maybe it is actually the way forward-I think it is pretty clear by now that man made climate effects aren't going to be stopped, so we might as well get colonising the solar system instead.

Regards making a modern Apollo-here's a far simpler parallel. The UK's aborted rail electrification scheme. One of the reasons it went hugely over budget is the loss of corporate knowledge, after BR was broken up and all the boffins who knew how to put electric string up retired. In a mere 25 years, the seemingly piddling skill of putting wires over trains has been lost, as well as the lost quarter century of development in OHL technology. The thought of what NASA has lost in 50 years, for something so much more complex, is frightening.

41:

They built one years ago. How else would you explain the Ryugyong Hotel?

42:

If it's going to be a circumlunar flight, then the target date should be December 21, 2018 - the 50th anniversary of the Apollo 8 mission launch.

43:

If the objective is purely 'safe round trip to and from the moon' then maybe what is needed is greater simplicity in design and more travel time rather than the current emphasis on increasingly greater complexity and fast travel time.

Also, why must travel to the moon be only one uninterrupted push? Fine - back in 1969 there was concern about how long it was safe for a human to be in space, therefore faster travel time (3 days each way) was a prudent idea. Nor was there any conveniently orbiting space station. But we've 50+ years of data, materials, resources and best practices on how to keep astronauts healthy/alive in space. May as well use them.

What would be the minimum new tech needed in order to launch a space ship to the moon from the ISS assuming no particular speed limit in traversing between Earth and Moon orbits?

If slow-boat-to-China space travel becomes publicly accepted as sensible and cost-effective, this would open up the possibility of Earth-Moon travel to more countries and private corps.

44:

"That's the 50th anniversary of the launch of Apollo 11."

is not unusual, or in retrospect unexpected. It follows two historical patterns.

The first pattern is the inevitable time delay between exploration and colonization. At the turn of the (last) century, the race for the poles was the Victorian equivalent of our race for the moon. Once the flags of Britain, Norway, etc. had been planted at the south pole, national prestige was satisfied. Afterwards, nobody bothered much with Antarctica for about another half century, until the first international geophysical year (1959). Since then, the continent has been studded with permanently manned scientific bases and weather stations. But nobody has ever bothered to try to colonize Antarctica on a large scale.

Mostly because Antarctica is a crappy place to live.

Yet it is far more inviting, far cheaper/easier to colonize and to get to than the Moon or Mars. So if history is any guide, about a half century after the Apollo program (within the next ten to twenty years) we can look for permanently manned stations in orbit, on the moon and maybe on Mars. The ISS would be the first of these stations. But don't expect massive colonization anytime soon. Our species simply won't move in large numbers to anyplace where we can't walk around outside in shirt sleeves for at least part of the year.

The second pattern is that government funded exploration (Ferdinand and Isabella paying for Columbus’ voyages, Jefferson sending Lewis and Clark westward, Kennedy pledging to land a man on the moon, etc.) is always followed by true colonization being performed by private enterprise (the Massachusetts Bay Company, settlers travelling the Oregon trail, Dutch East India Company, railroads spanning the west, etc.). In fact, the early colonization efforts in the Americas were the work of the world’s first stockholder corporations. Planetary Resources, Inc. (asteroid mining) and SpaceX (private space launches) are just the first corporations being formed to colonize and exploit the “New World” of the Solar System. Which means we won’t be colonizing planets.

45:

About NK: It's far more likely that they will try to put a human on the Moon by 2026. According to the New York Times, that's what the "Dear Leader" wants

46:

Theoretically, SpaceX doesn't need a dedicated LM as the capsule can use rocket propulsion to land. With a delta v of less than 2.5 km/s for descent the fuel is not much more than the capsule's own mass. With refueling on the Moon for ascent, the craft might just need extra fuel tanks to make this a viable approach for lunar tourism.

While I doubt this will be used anytime soon, this approach might just make more sense than the approach used by Apollo.

47:

I don't think "Trump and Pence both being impeached" would have an appreciable effect. Anyone finding themselves suddenly in the hot seat (not to mention the rest of Congress) will be quite eager for some good, unite-us-all, news.

48:

"Trump is nothing if not an egomaniac,"

I get the Make America Great Again appeal of spaaaace.

But this would require Trump to act now for something that wouldn't pay off until 2019, and get congress on board for it because it'd need funding, and to be willing to give money to Musk.

That just seems a bit tricky. Congress will be very focussed on (a) tax cuts for the rich, (b) re-election in 2018 and (c) tax cuts for the rich. Musk has dissed Trump.

I guess this could meet (b) if you get a lot of propaganda value out of it before it happens. But really... Musk has dissed Trump. Trump's just getting too toxic, even for someone like Musk who tried hard to be in because he's smart enough to know that US R&D has always relied heavily on US govt funding.

49:

It's looking like the first Falcon Heavy launch may be pushed to early next year - but it's not the rockets fault. They have to finish fixing the launch site they blew up last year before they can take the one Falcon Heavy needs and do the modifications it requires to launch - and they're running out of time this year for it.

There is some evidence that NASA is looking at moon missions though. Well sort of. They are in the process of getting proposals for COTS type missions to the Luna Surface. COTS is the Commercial Orbital Transfer System - ie commercial flights to supply the ISS. They want commercial transport services to the Moon - what for and where exactly haven't been specified yet. Maybe a moon base announcement instead?

50:

Soft moon landing optional, too...

51:

On resurrecting 60's era Apollo technology, in particular the lunar excursion module. NASA did try building new F1 Saturn first stage engines. Good article here on how that went. As others have said, lots of knowledge lost, components and materials unavailable and replaced, new manufacturing techniques. Sometimes it is just easier to start from scratch.

52:

Well, I did suggest putting both "The Donald"and Kim Jung Il on Rockall on another site. https://en.wikipedia.org/wiki/Rockall

53:

While that's a part of it, it's mostly a case of an over-ambitious new technology.

There was a load of electrification done in NW England in the last few years, and that was mostly done with merely normal overruns on time and cost (the Liverpool-Manchester wiring was three months over on a three year project; Liverpool-Wigan (connecting Liverpool to the mainline to Scotland) was on-time, Manchester-Bolton (similarly connecting Manchester to Scotland) had a three month delay after a tunnel collapsed but they've got that time back since, so is back on schedule.

This work was done by the conventional techniques and ran more-or-less as expected.

The problem was the GWR electrification, which ran into a series of problems.

First, they bought a new, very expensive engineering train (HOPS) which was supposed to do the whole job in a single device, so it had a drilling section to drill holes, a construction section to put gantries over the line and a wiring section to string the wires onto the gantries. The traditional technique is to do those three jobs separately.

The problem was that the drilling bit of the HOPS train didn't work properly, which meant that the other two bits were waiting around for the holes to be drilled, which meant it was massively inefficient.

The second big problem was that the engineering diagrams telling them where the wire-runs are for the signalling on the line were completely wrong (the line was resignalled in the 1960s and BR retained both the 1960s diagrams and the 1920s ones for the previous system; it seems that Railtrack threw out the wrong set of diagrams in parts of the line), resulting in the holes that were drilled going straight through signal wires and shutting down the signalling - which shuts down the line, costing a fortune in passenger compensation. Ultimately, they're digging the holes by hand (in some areas, literally with hand shovels; in others with diggers) and using the HOPS train only for the gantries and wiring.

GWR is actually supposed to be resignalled, but the plans for the new signals put them on the electrification gantries (very sensible, means you don't need two sets of structures along the line and gantries don't block sighting of the new signals). However, that means that you can't do the new signalling first, so you have to keep the old signalling going until the gantries are up.

There are a bunch of minor issues arising from inexperience - taking an example from the NW, the cock-up at Huyton station where they wired the line, then moved it to put in a new platform, then had to move all the wires to line up with the moved track - but that's created a bunch of minor delays, not the complete disaster that GWR has been.

A bit of political courage would have meant no real need to cancel a load of electrification projects: just take GWR on the chin and get on with wiring up the rest of the country, letting the NW and Scottish electrification project teams (I haven't mentioned Scotland, but they've been wiring up great tracts of the country on-budget and on-time) take over rather than letting the GWR team carry on cocking things up.

54:
that man made climate effects aren't going to be stopped, so we might as well get colonising the solar system instead.
We can't manage a big biosphere with lots of redundancy and slack in the system, so we should move to small tightly coupled ones instead?
55:

Off topic, but reading the news, such as

https://www.nytimes.com/2017/09/27/us/politics/scott-pruitt-epa-justice-department-funding.html

made me realise just how accurate teh Delirium Brief is, in the way government departments can be compromised and taken down. I had thought/hoped it was just (?!) satire.

56:

Doing one won't preclude the other, lessons learned living off-planet could prove helpful in maintaining livability dirtside.

57:

ade me realise just how accurate teh Delirium Brief is, in the way government departments can be compromised and taken down.

Nope: I based it on extensive (drunken, pissed-off) conversations with civil servants who've been on the receiving end of it; and their accounts meshed with observed news reportage, after taking into account the political/ideological editorial biases of the news outlets.

58:

While that's a part of it, it's mostly a case of an over-ambitious new technology.

In some cases the delays in improvements to rail in the UK are due to us being an early adopter of rail tavel. The electrification of the Glasgow-Edinburgh line was made a lot more complicated and expensive because of a tunnel on the route that was too low to take overhead power catenaries. It had been dug to accommodate (small) steam locomotives about 150 years ago on a neat-fit basis. The solution involved digging out the floor of the tunnel to lower the rail track, a cheaper solution than reboring a new tunnel but still expensive and time-consuming and of course it took that section of line out of service for several months. The track either side of the tunnel had to be regraded and relaid to match the lower line in the tunnel, new flood defences implemented around the tunnel entrances etc. It wasn't a simple matter of stringing a lot of wire despite the beliefs of the rose-spectacled BR-booster brigade.

59:
I think it is pretty clear by now that man made climate effects aren't going to be stopped, so we might as well get colonising the solar system instead.

Until climate change results in an atmosphere that resembles venus, colonising earth is going to remain waaaaay easier than colonising anywhere else.

If you're hoping for some utopian scifi fix for all our woes, I wonder if you'd be better off gambling on the invention of a magical CO2-eating, diamond-pooping, atmosphere-reprocessing system than a bunch of functioning independent colonies off earth.

60:

The Soviet RD-171 engine for the Energia produced more power than the F1 and was more efficient, throttleable and it pivoted. It still flies in a cut-down version as the two-chamber RD-181 (Atlas V) and the single-chamber RD-191 (ATK Antares). The problem the F1 had with turbulence was solved by the Russians by using multiple chambers and bells rather than energy-sapping baffles around the F1's gigantic injector plate.

61:

Yeah; a cost-effective electricity-driven technology for reducing and polymerizing carbon — ideally to diamond or one of the exotic hyperdiamond allotropes, but failing that even graphite would do — would, in the long run, be a solution. Just replace all our concrete structures with diamond bricks! Long lasting, durable, heat resistant, high compressive strength (and not bad at tensile, either, if you can make them flawless), and every 1Kg of diamond pulls 3.7Kg of CO2 out of the atmosphere.

What's not to like? Well, the "and here a miracle happens ..." bit of chemical engineering in the middle. But that's about all.

62:

If the bricks are pretty, it doesn't even have to be cost-effective for starters. Just use them to construct billionaires' mansions until the price comes down.

63:
What would be the minimum new tech needed in order to launch a space ship to the moon from the ISS assuming no particular speed limit in traversing between Earth and Moon orbits?

That would let you use ion drives, which have massive delta-v.

The same technology gets you to Mars orbit in not all that much longer flight time...

64:

There are a couple of velocity constraints.

Firstly, outside the Van Allen belts, astronauts are exposed to high energy cosmic rays. Solar storms are probably survivable with shielding, but the high energy nuclei come in with GeV energy and dump it all in soft tissue. They're very damaging to human bodies, and it's not feasible to shield against them (you're looking at a half-thickness of maybe 50cm of water to attenuate them — so on the order of a tonne of shielding per square metre of surface area for your shelter — and they come in from all directions, not just the sun (as is the case for charged particles emitted during a solar flare). Minimizing exposure to this shit is a good idea, which means minimizing trip time.

Secondly, for every 24 hours spent en route, you need to budget for roughly 3Kg of drinking water, 1-2Kg of food, and 550 litres of oxygen (about 800 grams, but allow for leakage from the ship: it's impossible to make a spacecraft 100% airtight). So that's 6kg of consumables per day per astronaut. For an 8 day Apollo Block 1 mission (3 astronauts) that meant 144Kg — plus cooling water for the suits — but if you go from a 3 day flight profile to a 30 day flight in each direction you rapidly end up schlepping extra tonnes of provisions to lunar orbit, which in turn means tens of extra tonnes of fuel/reaction mass ...

65:

viable launch direction is East into the Sea of Japan

Not that this is particularly relevant to the OP, but a launch due south out of the/a west coast site isn't obviously out of the question, at least modulo the general bizarreness of the concept. There's already a space launch facility at 39.662 N, 124.707 E and Cape Changsan sticks out about as far west and has the advantage of being down range from Pyongyang.

(The over-Japan trajectory question also came up this morning in connection with the possibility of a live-fire ICBM demonstration.)

66:

Re: '... outside the Van Allen belts, astronauts are exposed to high energy cosmic rays.'

Since Musk is already manufacturing the spiffiest (most esthetic and efficient) solar panel roofs for and on this planet, he's probably also bright enough and a good enough marketer to figure out some uses for all that free energy.

New $logan: What doesn't kill you can make you a killing.


67:

You also want to spend as little time as possible in the van Allen belts, ion drive craft tend to spend quite a lot of orbits spiralling through them.

68:

ANd of course unspeakable wanker Grayling has made it worse, by totally cancelling all fur=ture electrification ( other than very small boits) thus ensuring that the just-regained knowledge-base is competely eroded AGAIN.
Rather than "going slow" & continuing with small electrifications & progressing slowly.
Together, of course with is:
Electric cars good, doiesel cars bad policy, the exact opposite of that on the t=railways.
Peoiple HAVE noticed & questions a re being asked, but one reason Mr G is where he is, is that he's a very very smoothy, slippery bastard of the first magnitude.

69:

Now that NASA AND Roscosmos have announced, it will begin to acquire bureaucratic momentum. As that builds, it'll be harder and harder to stop. The Orange Nutcase will, hopefully, be gone before 2019 (damn, I owe a fan-friend $5 - I was betting at least the charges to come out by the end of Sept), but... and along with old Cold Warriors, I see a fair number getting behind this.

Hmmmm... perhaps I should talk to the people I know, who can talk to people, and also to my Rep and Senators about supporting this as a gigantic anti-divisive effort to bring the US back from the brink; i.e., all politics is local).

70:

That's completely incorrect. I believe the correct word is "shrapnel".

71:

Here's an alternate: the US and Russia, possibly with India, on this; the ESA maybe in, or maybe on its own, and China, on its own, a three-way race.

72:

Snarl.

The original plan for the Shuttle was about a quarter the size. A co-worker, around '83, told me he had a buddy who worked at Rockwell, I think it was, and it was supersized, per the Pentagon, to be able to carry a specified number of "nuclear devices".

73:

Nope, the Shuttle wasn't sized for nuclear weapons.

It had a payload bay the size it was specifically to carry a KH-11 spysat back from orbit. The mission spec originated in the late 60s/early 70s when the spysats still parachuted film capsules back to Earth — the idea was to retrieve the satellite and relaunch it with new film canisters. It was obsolete due to the advent of decent video cameras before the shuttle ever flew.

A side-effect was the re-entry profile of the shuttle. Given the orbital inclinations it could reach, a mandatory requirement for carrying TOP SECRET spy satellites home from orbit was that it must never cross Communist territory (USSR and China) at anything less than full orbital velocity. So it had to be able to do the full re-entry over the Pacific, in about 4000-6000 miles, which meant dumping a lot of energy in the form of heat, hence the interesting heat shield. Which, indirectly, led to the loss of the Columbia, when a damaged wing tile let superheated plasma into the aluminium support structures leading to break-up during re-entry. If it had been able to re-enter gently over a much longer flight path the energy flux could have been much lower.

74:

Mateus Araújo @ 18:
HOLY SHIT. I had never seen a solid-fuel rocket exploding. Forget Dragon 2's launch abort system surviving that, can *anything* survive that?

If it was built to withstand the pulse for an old fashioned "Orion", the explosion could boost the capsule away from the blast.


bevans1 @23
Could we put Donald Trump on the moon? Please? ASAP. 2019 at the latest.

My first response is "What has the moon ever done to you?

But upon reflection, maybe he can take Newt Gingrinch with him. Bundle in Paul Ryan and Mitch McConnell and it would be a perfect foursome.

Return flight optional.

Why? Just leave them there.

anonemouse @ 54: We can't manage a big biosphere with lots of redundancy and slack in the system, so we should move to small tightly coupled ones instead?

Maybe we could learn something that could help us manage what we've already got?

And if we start with the foursome I recommend, it would be no great loss if the venture failed.

76:

While we're on the subject of new technologies, China is building several reactor designs that have sat on the shelf for decades at this point. This includes traveling wave reactors and pebble-bed reactors. I'm unsure whether or not they're building molten salt reactors.

https://www.bloomberg.com/news/articles/2017-09-21/nuclear-scientists-head-to-china-to-test-experimental-reactors

77:

No! NO! Keep him here! Send me, PLEASE!!!

78:

I believe I've read you can find the simulator running that code online a couple of years ago.

And no, I don't mean the ancient game of Lunar Lander....

This gives me something to hope for... that there may actually *be* a 21st Century (barring a nuclear war....)

79:

An interesting article describing DT's spite pettyness & very long memory in a current context.
Very revealing, if true ....

80:

As you say that, I can't help but see the scene from Destination Moon....

81:

I don't know if they're still working on it. Someone, who may or may not know what they're talking about, said that when they tried using modern techniques, the results were too heavy.

I dunno... but *Goddess* (and I do NOT take Her name in vain), I want to see, live, an F1-B engine speak.... I never saw the Saturns go up, live, but I will go see this.

82:

They dropped it. The NASA HLV is going to fly atop five modified SSMEs instead, which are LOX/LH2 burners. Falcon Heavy should be a spectacle and a half — 27 Merlins burning in parallel — and if Musk gets to build his BFR, even the cut-down version will rival a full-up Saturn V for noisemaking potential.

83:

From that URL: donald-trump... con-man... huckster... scumbag
And that's just in the *address!*

84:

The F-1B was being considered for the side boosters as a replacement for the SRBs, the core stage was always going to be hydrogen burning shuttle derived engines and tankage.

One of the apparent reasons for the changing capabilities of the Raptor engine being developed for the BFR and NQSBFR, and the large number of engines for the size of rocket, has been the search for the sweet spot between engine mass, thrust and stability.

85:
What's not to like? Well, the "and here a miracle happens ..." bit of chemical engineering in the middle. But that's about all.

Yep. And for all that, it is still more likely than fleeing to some self-sustaining offworld colony. Only one ridiculous technical hurdle to overcome, you see.

86:

China already has a heavy launcher (which carries a bit more than the Falcon Heavy), a space station, a lunar exploration program, and is planning an automatic sample return mission for 2019(!). They will not carry a flag of the USA to the moon.

87:

Nope, Long March 5's payload is about the same as Falcon Heavy in reusable mode, i.e. about 25 tons. A Falcon Heavy flying as a one-shot stack (i.e. no attempt to recover the strap-ons or first stage) is good for upwards of 60 tons into LEO, maybe more.

I'll grant you the Chinese space program appears to be making slow but steady incremental progress along a path trodden by the Americans and Soviets, and they look like they'll be capable of doing the full crewed Lunar expedition thing in another decade if they want to go that route. But I think the USA is capable of beating them to it quite easily, from their current position.

88:

If you re-enter more slowly, with a lighter vehicle , you don't need the extreme heat shielding. That was the thinking behind Skylon...

https://en.wikipedia.org/wiki/Skylon_(spacecraft)

https://www.space.com/32112-how-skylon-space-plane-works-infographic.html

89:

"...no attempt to recover the strap-ons..."

I now have this irresistible mental image of a rocket taking off, festooned with bondagey leather straps supporting a frieze of big wobbly pink dildos hanging off the sides, all round, like the petals of a banana skin.

One of these things, coming loose, initiates a Kessler cascade, and in aeons to come Galactic historians record the cautionary tale of the ape species that shafted its own space programme with a rubber cock.

90:

I'm replying before reading all the comments... so usual disclaimers...

I used to repair breathing gear that was a development of a development of gear that was a version of the spacesuit breathing gear developed for the the Apollo era space suits.

I wouldn't use that gear for all the tea in China, and the previous generations of that gear were frankly terrifying. I've never touched or worked on the actual Apollo stuff, but if the LEM is/was anything even remotely like that, you'd be better off to burn the designs and blind everyone who's seen them. It was so full of basic mistakes that it's literally a miracle that anyone came back from any spacewalks. Design and fault analysis has come a long long long way since then.

Even as a layman... look at the Apollo 13 events. Setting aside some pretty obvious things about how to handle pure oxygen, they had 3 systems (for safety) and then they manifolded all three together (for convenience) so that a fail in one took out the other two. Urrgh, it's so horrible, kill it with fire! (oh wait, it kills itself with fire automatically)

91:

Piling on to Charlie's comment, a lot of the military and NASA merging of the shuttle to be used for both manned and unmanned launches came from Washington. After all it MUST be more efficient to develop ONE generalized launch system than separate systems for specific needs. Right? Logical? Politicians can't be wrong?

Which is why I think the F35 project only has about 30% shared parts between the 3 variants.

92:

And now they're going to use the BFR for suborbital earth-to-earth executive trips, earth-to-orbit, earth-to-moon and earth-to-mars. And mothball the whole 9 series. Interesting times.

93:

Latest info from Elon during his Australian talk.

https://www.youtube.com/watch?v=tdUX3ypDVwI

94:

I've said it before, I'll say it again -- at the time the Shuttle was laid out the US had virtually no experience of in-orbit assembly and docking of separate vehicles other than flying everything thrown up on a big single stack. Skylab was launched in 1973 and used Apollo components and proved a lot of the technology and operational requirements but by that time the Shuttle plans were well-developed and they were based on one-shot logistics, put the people and the payload up together because there was no certainty that two separate craft could find each other in orbit and successfully dock with each other.

Another factor that is often overlooked is the time it takes for a crew capsule to get to its working space such as the ISS or some hypothetical new version of Spacelab (which has no plans, no funding, no deployment schedule, not even Powerpoint presentations) which the Dragon capsule will need its spam-in-a-can contents to do anything useful in orbit. A Soyuz capsule with limited environmental capabilities can spend two days in flight before it matches orbit and velocity and docks with the ISS (there's a new but trickier launch process that is a bit faster at less than a day) whereas the Shuttle crew could get to work pretty much after achieving orbit since they took the workshop (and the toilet and the shower and the EVA airlocks etc.) with them.

95:

Ahem: not so fast.

My bet is that security concerns will kill ballistic point-to-point passenger service, unless it's terrifyingly locked down (e.g. no checked bags, hand luggage limited to teensy-tiny handbag, passengers subjected to pre-flight background security checks and serious pre-departure body searches, spaceports located at least 100km from destination and connected via maglev or hyperloop for the city-to-spaceport ride).

The final result will be a 40 minute flight time ... but an hour to get from city to spaceport, 2 hours for pre-flight security checks, an hour on the pad/in flight, an hour for customs/immigration at the destination, and another hour on the train to get into the target city, i.e. a six hour point-to-point journey with maybe 1-2 flights per week (due to cost/demand), as opposed to 24 hours by conventional airliner or bizjet leaving whenever the hell you want. (Oh, and you get business class bed-seats and in-flight internet aboard the airliner or bizjet, unlike the vomit comet.)

Possible loopholes:

1. If you fly ballistic, your checked bags follow by subsonic freighter and arrive maybe 12-24 hours later. Probably not problematic.

2. Maglev/hyperloop changes the "it'll take ages to get between destination city and spaceport — it's 200km away!" side of the equation from "adds 1-2 hours" to "adds 15 minutes".

3. Never underestimate the bandwidth of an ICBM full of SSDs flying point-to-point. (Tannenbaum's law updated for a new era.) Could compete with undersea cables for insane big data broadband requirements (e.g. shipping petabytes around on a daily basis).

96:

they were based on one-shot logistics, put the people and the payload up together because there was no certainty that two separate craft could find each other in orbit and successfully dock with each other.

Incorrect. The Gemini-Agena program developed that capability in 1964-66 (rendezvous and docking with target vehicle), and as if that isn't enough there was Gemini VI/VII in 1965 (rendezvous and station-keeping in space). And that's without borrowing Soyuz tech.

97:

Regarding the shuttle reentry profile, I remember there were lots of discussions after the Columbia disaster to change the profile to a gentler reentry. The problem was, while easier on the thermal protection system, a longer reentry would allow time for heat to conduct through TPS and get to the aluminum body of the shuttle, which was not designed to withstand it.

98:
for every 24 hours spent en route, you need to budget for roughly 3Kg of drinking water, 1-2Kg of food, and 550 litres of oxygen [...] extra tonnes of provisions to lunar orbit, which in turn means tens of extra tonnes of fuel/reaction mass ...

There have been year-long three-person missions in Earth orbit, and with ion drives the amount of propellant to move the whole thing to lunar orbit is pretty much negligible, so the supply situation should be fine.

vₑ ≫ ∆v changes everything.

99:

Ion drives are not a magic wand. Isp of existing ones (Xenon, I believe) are around 600-700, compared to the 380-450 of current leading chemical/cryogen rockets. Others on the drawing board may exceed 2000. But ion drives require lots of electricity to run, and produce stupidly low amounts of thrust—they're efficient but very, very slow to accelerate. Look at the time scales for the Dawn mission (an actual flying interplanetary ion drive probe) to get a feel for it — the 12 months Earth-Mars mission profiles presume chemical or nuclear-thermal rocket propulsion, not ion drive, which would likely take multiple years.

100:

The problem of ballistic flight has little to do with what you carry on the trip - so the additional checks of baggage and passengers are not useful and not likely. Similarly, it is not clear how keeping the flight terminus further away from city centers than airports already are is useful.

What you will likely see is that this will be limited to very friendly countries and subject to suspension if relationships deteriorate.

101:

Note that in the late 50s/early 1960s there was a parallel fear surrounding widespread use of jet airliners; that Soviet strategic bombers could stage to areas near civil aviation corridors off the US coast, out of range of primary radar, then "shadow" scheduled airliners to their destination airports, thereby getting extremely close to target cities before being detected.

In the event, this didn't happen because the Soviet heavy bomber threat was replaced by their ICBM capability. But I expect the emergence of ballistic passenger services to drive the same fear—that someone will replace a scheduled ballistic capsule with an ICBM in order to carry out a first strike. (Never mind smuggling a bomb on a ballistic vehicle, or hacking its guidance system to bring it down on a target.)

102:

The only link I could find for Tannanbaum's Law was this one Uh?
Kernel architecture? UH?

@ 101 - why bother?
Smuggle a bomb on to a large, preferably artic-type delivery truck, well sheilded inside the other harmless cargo, & do it after you've run truly harmless tat 200-500-times already, so that "it's another one of Joes lorries" applies ....
Cheap, too.

103:

Question - Does "BFR" expand as what I thought of when I heard it on the Radio 2 news? (yes Big, ah, Freaking Rocket)

104:

Ion drives are not magic, but the rocket equation is brutal; the ones on Dawn were apparently 3100s, so that would make vₑ ~30km/s. Transfer between earth and lunar low orbits is about 4km/s, which gives 10-15% of LEO mass being propellant. Higher specific impulses would reduce this further, though I may be missing a de-rating of √2 in the formula on account of the low thrust.

The 12 months Earth-Mars mission profiles generally presume unpowered Hohmann transfer orbits; powered flight would have an entirely different profile, much faster. The moon is basically too close to the Earth for ion thrusters to be practical — for lunar missions, ion thrusters increase flight time, while for interplanetary missions they reduce it.


Of course, if time is really no issue, one can use the interplanetary transport network... unlikely to be of any use for crewed flight, and doesn't really go to Mars, but has the nice feature of Mote-style magic points of entry and exit.

105:

Why even bother with running your "own" wagons several times? Send your bomb with a known haulier who has multiple movements every day, such as, say, Denby Transport for UK-France or reverse, or if working in the UK Eddie Stobart, France with Norbert Dentressangle, Austria with Spedition Berger. I could come up with those names from memory and Da'esh are quite capable of using a web search engine.

106:

Thanks gasdive @ 93 for posting the Elon Musk presentation Making Life Multiplanetary. Definitely a must see folks. Elon talks about SpaceX current missions and future missions: the BFR rocket, Moon Base Alpha, Mars missions, and Earth transportation. Should answer some questions.

Also on Huffpost: http://www.huffingtonpost.com/entry/elon-musk-mars-plan_us_59cdcee0e4b09538b5075502?ncid=inblnkushpmg00000009

107:

The first Agena docking attempt was a failure if you recall. The docking process required both craft to be launched within a quite short timescale because of exhaustion of consumables on both vehicles -- the ISS is only kept flying by the regular transfer of many tonnes of fuel, food, water, oxygen etc. each year. Long holds on the pads or recycling a launch for a week or two later was a regular occurrence back in the 60s and orbital rendezvous are heavily time-dependent. Modern launches are remarkably predictable and can often launch to the second, not so back then. There's also better computation available to optimise the actual rendezvous operations.

Going back to the Moon on a single super-heavy launcher that hasn't actually flown yet (the first flight of the Falcon Heavy was originally planned for 2012 or so, the most recent announcement says 2018 sometime) is stupid other than as a publicity stunt. A circum-Lunar flight could be carried out by two F9 launches, one for the service module and one for the crew capsule. A manned landing on the Moon might take something like six F9 launches, two to put a separate ascent vehicle down somewhere safe first (two would be better), the crew capsule, the inter-orbit service and transfer module and a separate descent module. Any failures or problems with an individual part of the operation doesn't necessarily stop the mission in its tracks and adds some resiliency. Various modules would also be reuseable if designed properly whereas a recreation of the Apollo-era flights with a single Heavy would require everything to be trimmed back to single-shot limits to save weight on the limited single stack.

108:

Was it Clarke who said that the problem with ballistic flight was that the toilet was out of reach for 1/2 the time, and unusable for the other half. There really will need to be a last call for the toilets before boarding.

109:

That would be the equivalent of landing the whole stack which makes no sense to me. Musk may however, be thinking along those lines in the future. The BFR reaches orbit, refuels, then descends and ascends at the Moon. Refuels and returns to Earth. That would require inexpensive refueling facilities and supplies. [While many have focused on water for LH2/LOX, SpaceX will want CH4/LOX. So a good supply of CO2 is needed, perhaps from dead comets. But that is quite far in the future, IMO].

110:

Is Elon Musk channelling the late great Cheslea Bonestall?
That picture of the base is pure Bonestall !
( I have a copy of "The Conquest of Space" somewhere in the book-pile (!))

111:

I should have watched his IAC presentation first. Looks like he does want to land his BFR on the Moon quite soon. Fuel will be launched from Earth rather than manufactured, although the LOX could be made on the Moon.

Looks like there is an opportunity in designing a good zero-g toilet, like that hinted at in Kubrick's 2001: A Space Odyssey. Lots of space in the BFR to add rotationally induced forces.

112:

More R A Smith, IMO.

113:

You are a sick, sick person, and need to see a psychologist, sooner rather than later.

Alternatively, if we're ever at the same con, I'll buy you a drink.... (I forget - are you US or OK?)

114:

And NO SINGLE SHOT to the Moon. What *needs* to be done, if it's not just a race or a stunt, is orbital stations here, and in lunar orbit. The latter is the Deep Space Gateway; we need something here, to, that *is* built for transfer purposes: fuel and supplies. Actually, it would seem reasonable to built a first take on the DSG in Earth orbit, perhaps hight than the ISS, but still below the Van Allen Belts, so that there may be less garbage in orbit.*

The a true spaceship, orbit to orbit. And then *all* of it's a lot cheaper.

* Y'know, as I typed that, I just had a thought: folks have suggested giant mylar sails to try to collect or knock out of orbit all the broken up satellites and the bits and pieces... here's one no one's proposed: a FLC of either gas, or something that on being fired creates a huge gas cloud, maybe 100km wide. It won't last long... but would work to deorbit a lot of small crap. Launch it east-to-west orbit, and it'll slam a lot of crap down, fast. I suppose we could call it the fartknocker....

115:

What *needs* to be done, if it's not just a race or a stunt, is orbital stations here, and in lunar orbit. The latter is the Deep Space Gateway;

I rather suspect that the L5 Society agree with you, and right now are turning cartwheels at the hope of their disbandment ;)...

116:

Bonestell worked with Willy Ley and Wernher von Braun. He illustrated their books. And when you're designing a BFR-scale rocket (as Ley and vB were, in the early 50s) design convergence will tend to impose certain constraints on you.

117:

All this "we lost the knowledge/information/skills/whatever" so we can't do it." makes me dangerously frustrated.

The idea of documenting the how, what, and why of any research has been around for some time. In the "soft" science of anthropology, they are suppose to document everything so that any future anthropologist, or anyone really, we be able to use it. It could be language, religions, anatomy, or just anything. This is not impossible, it just has to be habit, albeit very tedious habit sometimes.

Of course, anthropology was started to preserve something of the societies being destroyed, quite often deliberately, so there was only a limited time to save anything, and even if the destruction was not happening, well anything with humans in it changes. Also just excavating something is destructive. So document everything, all the time, or lose it, probably permanently.

118:

Back to the original topic for a moment, I don't think it will happen. Too much risk of having to make the Apollo 11 speech that didn't have to be made in return for reminding everyone that it was another President who presided over the accomplishment. Not enough glory for the Tremendous, Really Great leader and too much risk.

119:

Finland used a similar tactic in their war against the Soviet Union although it was military aircraft they were shadowing.

https://owlcation.com/humanities/World-War-2-History-Finland-Responds-to-Massive-Soviet-Air-Raids-Against-Helsinki

120:

Getting in the mainstream. The first 15 minues of Newsnight tonight was on Elon Musks presentation.

121:

Re: '... additional checks of baggage and passengers are not useful and not likely..'

Two hypotheses:

1- Such flights would probably require specialized suits for everyone on board. (Billionaire frequent flyers might spring for their own custom fitted space suit. The mechanic, scientist or other staffer that gets sent up for a one-time or even regular intermittent visits - no way.)

2- Fares charged by the ounce. (Some penny-pinchers might try to severely dehydrate themselves before weigh-in, therefore a pre-boarding medical quick test would probably be part of the passenger screening.)

Combining the two: travelers would dump whatever clothes they arrived in at the spaceport, wear only their undies in the assigned spacesuit, and then dress in esthetically pleasing (and marketing researched) 'complimentary' jumpsuit upon arrival.

Cachet is walking around in/owning 'genuine spaceport arrival' jumpsuits. Could probably merchandise the hell out this including distinctive designs for each spaceport and/or year.

122:

There's some interesting stuff being done with metal fueled ion drives by Paddy over at Neumann Space. Particularly the possibility of reprocessing mag-alloy space junk fragments into the fuel. Have a look over the different Fuel of the Week options for some interesting commentary. I like the one about the possibility of using astronaut shit to make carbon fuel elements.

123:

Wow these guys are literally 2km down the road, they must have been over the moon to have the IAC in their home town.

124:

Existing Ion drives e.g. those on Dawn have an Isp over 3,000 s, and some quick googling indicates that exotic designs reasonably go up to 10,000 s or more.

The problem with looking at the Isp of ion and similar electric thrusters that people tend to overlook is that Isp vs. thrust is really just a direct tradeoff. Given a certain amount of power available, you can either spend it accelerating a small amount of matter very fast, or a large amount of matter rather slowly. Existing designs are fairly efficient, so an ion thruster with a higher Isp is really just letting you choose spend your solar panels on slower acceleration for longer.

This same tradeoff exists with chemical and nuclear rockets -- the difference is just that in comparison, a chemical rocket is a shockingly violent conflagration putting out as much power as entire nations, while the fancier nuclear rocket designs start to look like insane maelstroms of barely controlled exotic physics dissipating as much power as entire planets.

Musk's system bypasses the whole Isp issue by being based on in-flight refueling. If you start in LEO with full tanks and 7km/s Δv, there really are transits to Mars that are only 3 months, which is much faster than you can achieve with any reasonable ion drive based system.

125:

I've seen this Deep Space Gateway sort of idea proposed a lot, but I just don't really get the necessity. Perhaps you can explain?

I understand that refueling high up in Earth's Hill Sphere, e.g. L2 or a distant retrograde orbit around the Moon means that you get a nice 3 km/s boost as you head out to parts unknown, which is useful. However, the cost is that you had to haul all those supplies up there.

A deep space only ship is also not really as useful as it sounds at first. Primarily, you really want to be able to use aerobraking for Earth and Mars. Complexity wise it really doesn't hurt if your ship can actually land on those planets, too.

Even with the Moon, that SpaceX proposal seems rather nice. Apollo, after all, did haul its reentry vehicle all the way to Lunar orbit -- Musk is just proposing to land it too (with in-space refueling), which means cargo and people go from surface to surface without a lot of fiddly loading and unloading.

126:

They're actually proposing that the BFR can refuel once before landing on the Moon (in a highly elliptical orbit, I believe) and then has plenty of Δv to land, take off again, and fly right back to Earth.

I assume the math works out OK. I believe the ship needs to be capable of approximately 6-7 km/s for the stated purpose of flying to Earth directly from the Mars surface, which is similar to its other job as an orbital second stage. Just a quick estimate seems to show this is also sufficient to land and return from the Moon.

127:

although the LOX could be made on the Moon.

I keep seeing folks say this. And to me it sounds like the "space cadet" meme that Charlie talks about.

It's one thing to have the basic ingredients for LOX. It's quite another to make and STORE enough to fill up the tanks for a rocket to use to get back to earth. That's an industrial process. How do we build that before we have the LOX to use in returns?

Never mind the, ah, somewhat harsh environment where all this has to take place. Is this all automated? To a point never achieved on earth? Or maybe there's a crew living there to operate this fueling station. Oh, yeah. Stick the landing cause there's no attendant in a pickup truck to run a few gallons out to you if you're not close to the pump.

128:

anthropology ... So document everything, all the time, or lose it, probably permanently.

Must be nice to operate where there are no time/money budgets.

In my consulting work for clients I try and take copious notes, more and more into an Evernote account for each client. And still I go back to repeat something done a year earlier and wind up trying to figure out the magic I obviously didn't write down after step 14.

When you're doing one or a few off, you wind up with no real way to test what documentation you do have. And since most of the time its only use is by the people who created it in time near the creation, the missing bits are not at all obvious.

But better yet is when in the past you went out and buy an off the shelf "black box" that has not be made in a decade or few.

I have friends who have and do work in industrial plants and such things are the bane of their existence. And all of them somewhat bemoan the loss of Radio Shack and old time auto parts stores where you could go buy a widget/part to get something done.

129:

I'll say it again -- at the time the Shuttle was laid out the US had virtually no experience of in-orbit assembly and docking of separate vehicles other than flying everything thrown up on a big single stack.

Doesn't mater to my point. The shuttle was turned into a truck and a cost budget setup before anyone had any idea of just how things would work. In the early 80s it was estimated that man rating satelite boosters added $10 mil to their costs. After all you're carrying a fueled bomb in the back.

And the entire reusability of the system was a farce. From many critics and from retired engineers who worked on it. As guy from Rocketdyne was say a few years ago, there turned out to be all kinds of systems that had to be taken out and checked but were designed into places where they were expected to NOT be taken out for 10s of missions at a time.

The shuttle should have been a test system THEN a decision made on what to do next. But politics dominated the process and we got a reusable space truck that wasn't either.

130:

And when are we going to see the movie version of Footfall? I. WANT. IT. NOW.

131:

I try and take copious notes... still I go back to repeat something done a year earlier and wind up trying to figure out the magic... When you're doing one or a few off, you wind up with no real way to test what documentation you do have

Yep. We have a wiki at work, and I trade off repeat tasks with a coworker so we test each others documentation. It reduces the amount of implicit knowledge, but that will never get to zero. One side benefit is that it also reveals shortcuts/stupidities in the process when some other monkey has to grind the organ for a while. The wiki gives us change tracking etc, when much of the rest of the company runs on MS-Word with all the attendant problems.

Oh, and this week: a shared VeraCrypt encrypted filesystem, so we can securely share word documents. I have no response to that.

If nothing else this should be part of your risk management/bus plan ("what if X goes under a bus"). Or if you think of yourself as a a professional rather than a mindless corporate drone, part of being a professional is doing your job properly, and that includes making sure there are no single points of failure as best you can, including you.

132:

When are we going to see any really good movie adaptations? I thought the adaptation of 'Do Androids Dream of Electric Sheep' was good, albeit not much like the original. Beyond that I struggle to think of any good adaptations. Some like 'I, Robot' were like horrid mirror image negatives, exactly reversing the message of the originals. Most are just a boring series of jack-in-the-box 'scares' and explosions.

133:

Soyuz cosmonauts have survived both an abort from the pad when the launch vehicle went boom, and an abort at hypersonic speed when staging failed. So we know that launch escape systems can work.

As far as I recall the US has only had one crew escape system used outside intentional tests, but Google is unhelpful. So, from unaided memory:

During the Apollo era NASA needed to know if their clever system would indeed get astronauts out of an exploding rocket, so after paper calculations and ground tests they loaded it onto real rockets and manually set it off in mid-air. One was headed up to high altitude (120,000ft, maybe?) when some part of the booster went pear shaped. While the humans were still gasping and reaching for controls, the automatic escape system detected the problem, blasted the dummy crew capsule free, and fired the escape rockets to get clear; when the time was right it popped the parachutes and returned the crew capsule to Earth intact. Engineers didn't necessarily learn anything new from that test but the machines worked exactly as they were supposed to.

I'll welcome any corrections or additions from anyone who has a better source than my own years-old memory.

134:

The shuttle should have been a test system THEN a decision made on what to do next. But politics dominated the process and we got a reusable space truck that wasn't either.

There was no budget for anything better. It took the bottomless pockets of the US DoD to part-fund the Shuttle project as it was, no-one in Congress was going to cough up the money for man-in-space otherwise. Apollo was done, the last few flights cancelled due to lack of interest. A couple of S-1Bs and an S-V were expended on the back-of-a-fag-packet Skylab project based on Apollo hardware that was paid for and sitting on the shelf (command and service modules, docking equipment, a repurposed S-V fuel tank structure etc.) but that was it.

If you wanted man-in-space after Apollo, there needed to be a reason for them to be there other than going round and round in orbit and then returning to Earth. That had been achieved by Mercury and Gemini. Going to the Moon? That had been achieved by Apollo. What was next? The robots were flying, doing the Deep Space job of landing on Mars, flying the Grand Tour, earth observation, communications etc. and the need for man-in-space was decreasing visibly while the cost of man-in-space stayed the same.

They needed a space truck. What they ended up with was a space mobile workshop with a cabover, in part because they couldn't guarantee they could get a crew to an unmanned space truck already in orbit reliably. I'm surprised they could actually get the money for what they ended up with and keep it flying for as long as they did.

135:

>> Isp of existing ones (Xenon, I believe) are around 600-700, compared to the 380-450 of current leading chemical/cryogen rockets

I think, perhaps, you might have conflated NTRs, which do tend to run in the high hundreds to perhaps 1,000sec with ion drives, which ran in the low thousands range 1,000 to 5,000 sec from the outset. I will just add that the further one has to travel, the more bang for the buck you get out of high Isp/low thrust motors. Mars is one of those destinations where you really can't just ignore the kind of ramp up time you get with limited acceleration the same way you can for outer System missions. This may be one of the reasons that systems like Vasimr and other types of motors that allow you to trade off thrust and Isp are as trendy as they seem to be.

136:

>>And when are we going to see the movie version of Footfall? I. WANT. IT. NOW.

Footfall, I don't have anything for you, but how about Ringworld? Courtesy of Jeff Bezos: https://www.nextbigfuture.com/2017/09/amazon-making-ringworld-snow-crash-and-lazarus-one-tv-series.html (Oh and Snowcrash and Lazarus, which I had not heard of before this, too)

137:

This same tradeoff exists with chemical and nuclear rockets -- the difference is just that in comparison, a chemical rocket is a shockingly violent conflagration putting out as much power as entire nations

Note for readers: the first stage of a Saturn V, at full throttle, put out roughly 60Gw of power. This is approximately the same as the entire British national electricity grid, and about one-fifth of the USA's power generation capacity.

(Admittedly it only did this for 168 seconds.)

Musk's just-announced redesign for the BFR is about 50% heavier than a Saturn V, so unless it accelerates rather slowly for a launch vehicle it probably matches 7-10% of the power output of the UK during the first stage launch burn.

I think a good way to get a wild-assed-guess handle on the energy budgets of space launches is to use something that is intuitively obvious — nuclear explosions. An S-1C first stage burns through 2300 tons of fuel in under three minutes. Let us approximate that chemical fuel and oxidizer to its own weight in TNT (the chemical bond energy is of the same order of magnitude); that makes a Saturn V launch energetically equivalent to roughly a 3 kiloton nuke, and a BFR to a 4-5 kiloton device. (Current SpaceX and Soyuz launchers are disappointing battlefield yield devices.)

138:

Musk's just-announced redesign for the BFR is about 50% heavier than a Saturn V, so unless it accelerates rather slowly for a launch vehicle it probably matches 7-10% of the power output of the UK during the first stage launch burn.

The Saturn V burned 10% of its entire fuel load before it cleared the tower. It accelerated like a constipated pig to start with, by the time the first stage tanks were empty the stack was pulling 4Gs (in comparison peak acceleration for the Shuttle was 3Gs). Big rockets are slow because they're heavy with fuel because they're big and they need to carry a lot of fuel to get off the pad at all. It didn't help with the Saturn V that the F1 engines were crude and inefficient requiring a lot of fuel and oxidiser to achieve their purpose.

The much-derided Shuttle's thrust-to-weight ratio at liftoff was considerably more than the Saturn V -- about 1.7 for the Shuttle vs. 1.2 for Saturn V. The current family of SpaceX Merlin engines are a lot better than the F1 in terms of Isp but lag behind the industry LOX/RP best-of-breed in terms of efficiency.

139:

I think a good way to get a wild-assed-guess handle on the energy budgets of space launches is to use something that is intuitively obvious — nuclear explosions.

Intuitive, but nope. Most of the energy of a nuclear explosion is emitted from the core at the speed of light and even the particulate emissions are in that speed range (neutrons at about 0.5c etc.) Chemical explosions are limited to the speed of sound in the ambient medium, waaaay slower so even if an entire Saturn V stack blew up it wouldn't be anything like a nuclear explosion. A lot of the LOX and RP-1 in the first stage would be blown away in the shockwave and not actually combust in the core, it might burn in the outer shell of the explosion a second or two later, an eternity in terms of a nuclear weapon's explosion.

140:

Re: ' Musk's just-announced redesign for the BFR ...'

No idea what Musk's redesign is despite watching the video which was very interesting.

However, I get the impression (because I don't understand this stuff) that folks seem to think that whatever fuel is used, it can only be that one fuel type. Is this a fixed constraint based on experience or is this a case of 'we've always only ever used one fuel type within any one launcher/rocket/ship'? *

By 'one fuel type' I mean: always some mixture of gasses or some mixture of solids.

If not a constraint, then what combinations of fuel types haven't been tried yet that might work?

Also, materials sciences have probably improved considerably. Specifically, if you could repackage the entire capsule and/or the equipment** on board into something that's much lighter, you'd save on fuel. So what could you change here?

Food & water - ditto improved tech for recycling esp. water. One of your earlier comments specified X amount of water per astronaut per day. However, within a closed system with decent water recycling, total water loss would be minimized. Therefore the amount of water shipped up and out per launch would depend on the number of crew/passengers only - plus a bit to spare. (Water recycling tech must be improved to the point of close to 0% loss if you have any hope of long interplanetary trips regardless of crew size.)

* My non-NASA-tech house allows for at least 4 different fuels: a different fuel for various different applications/equipment. (It's been third-party professionally rated as very energy efficient. Had it checked because I had to get some related work done on it.)

** Come on - the ordinary smartphone is has replaced whole buildings full of IBM computers, so there's got to have been similar mass/weight savings in space capsule tech. If not - then this is a problem area that should be addressed.

141:

The incident you're thinking of was wonderfully well documented on video!

Little Joe II abort test

142:
However, I get the impression [...] that folks seem to think that whatever fuel is used, it can only be that one fuel type.

I'm not sure I really understand what you're asking.

Real-world rocket/satellite systems typically use multiple fuel types. As an example of a pretty boring modern comsat launch on an Atlas 5 rocket, you'd see: Solid rocket boosters, Kerosene / LOX first stage, Hydrogen / LOX second stage, a Hydrazine boost rocket on the satelite, and finally Xenon-based ion thrusters for final orbit circularization and long term station keeping.

Choosing which type of rocket to use is a matter of tradeoffs regarding various things like thrust, efficiency (Isp), cost, stability at room temperature, etc. There's no system that checks all the boxes, and some of the good theoretical ideas like NTR involve nuclear reactors (or even better, gaseous nuclear reactors existing in a vortex of uranium hexafluoride plasma) which have some issues (such as not existing).

SpaceX's BFR system is using Methane/LOX for a couple reasons: we know how to synthesize it on Mars, it has decent efficiency (better than Kerosene), it's cheap, and importantly, both are cryogenic but moderately so (at about the same temperature) so it's possible to keep them stable in space with just some insulation.

There aren't any chemical fuels that we know of that are really significantly better, and the more exotic ones tend to be horribly toxic or unwieldy. The next step up for launching from Earth is probably a nuclear rocket. For space, you can also consider ion propulsion but it doesn't really work well for the Moon or Mars.

143:

The Lord of the Rings and those Harry Potter movies I actually watched were pretty good, as was the adaptation of Holes. (I haven't read the book, but it made a great movie.) And one has to admire the integrity of Guillermo del Toro in refusing to plug a romance into Mountains of Madness.*

On the other hand, I never went to see any of The Hobbit movies, for what I hope are obvious reasons, and generally don't like movie adaptations. So making a good movie from a book is possible, but it happens infrequently.

The other book series I want to see made into a movie is Varley's Gaia series. Titan, Wizard and Demon would make awesome movies. This little piece is the closest anyone has gotten so far.

*IMHO he should have created a romance, then had her killed by Shoggoths - that would have brought the horror home nicely.

144:
One of your earlier comments specified X amount of water per astronaut per day. However, within a closed system with decent water recycling, total water loss would be minimized.

Keep in mind when thinking about real-world systems that there are a lot of pesky engineering difficulties that get in the way of nice Science Fictiony tech.

For example, the ISS actually has quite good water and air recycling already. However, one of the realities of life support machinery is that when it breaks down, you still need it. The solution is that you need backup systems, spare parts, backups of the backups, and for ISS the final backup is escape capsules.

(This is actually sort of hilarious in poor SF: how many times have you seen people gasping when the life support fails? In reality, you're fine for at least hours to days, at which point you dig some oxygen candles and CO2 sheets out of the closet.)

Anyway, there's no escape from a Mars transport ship (well, unless they fly in fleets) so you have to engineer in backups for all these systems. What if the water recycler breaks? Do you carry two sized for the whole crew? What if it's a design flaw so they both break? What if the solar panels break? And so on.

All these backups, spare parts, and so on add to mass of the system. Depending on the length of the mission, there isn't necessarily any benefit from using the high-tech kit compared to just carrying more water and CO2 scrubbers. Either way, there's no way we're going to be growing food on board so the daily ration allowance is significant no matter what.

145:

I haven't read Lazarus, but I am looking forward to Ringworld and Snow Crash. (Snow Crash will be a lovely acid test for Hollywood Racism, as so many of the major characters are non-White. And if Hiro falls in love with YT I'm turning the damn thing off permanently.)

146:

whatever fuel is used, it can only be that one fuel type. Is this a fixed constraint based on experience or...

The more things that need to be loaded onto a launcher at the pad, the more complicated the ground equipment gets which means it's more expensive and more likely to go wrong. A Falcon 9 needs liquid Oxygen, Kerosene, Nitrogen and Helium loading shortly before launch. It burns the Oxygen and Kerosene, uses the Helium to pressurise the tanks and has Nitrogen thrusters for attitude control in vacuum when the main engine(s) aren't running. The BFR uses gaseous Methane and Oxygen for pressurant and attitude control, tapping it off the liquid propellants, halving the plumbing required.

Rocket manufacturing costs scale far more strongly with complexity than with size. The fewer components there are, and the fewer things you need to do leading up to a flight, the cheaper the flight is going to be.

147:

Re: Fuel types

Thanks - much appreciated! This exactly answers my awkwardly worded question.

'Real-world rocket/satellite systems typically use multiple fuel types. As an example of a pretty boring modern comsat launch on an Atlas 5 rocket, you'd see: Solid rocket boosters, Kerosene / LOX first stage, Hydrogen / LOX second stage, a Hydrazine boost rocket on the satelite, and finally Xenon-based ion thrusters for final orbit circularization and long term station keeping.'


Re: 'The solution is that you need backup systems, spare parts, backups of the backups, and for ISS the final backup is escape capsules.'

Okay - makes sense. However, assuming improvements in tech & materials over the past 50 years, this would mean that there would be even greater savings in mass/weight because both the primary and backup systems could be made that much smaller and less heavy (therefore requiring that much less energy to push).

Dumb question: Is it the weight or the space/volume taken up by the water that's a problem? If weight, then not much you can do about it. If space/volume - if you could make the water 'smaller', then at least you could save on the mass/weight & size for storage. Vaguely recall that water molecules can have interesting geometric shapes depending on temp. So, has anyone tried to condense water into a smaller 'size/configuration'?

The below is a refresher I found on the topic of 'water' but it looks to be about 10 years old, so lots of science probably done since then.

http://www.chem1.com/acad/sci/aboutwater.html

148:

Think you are being overly optimistic, roughly 85-90% of a rockets mass is fuel, and there's no way to make liquid rocket fuel magically weigh less. You can cram more in by cooling it down to a lower temp but that's about it.

149:
Is it the weight or the space/volume taken up by the water that's a problem?

In space, it's essentially always the mass (weight). To a first approximation, that's the only thing the matters at all.

The only case where volume really matters is for hydrogen tanks. Liquid hydrogen is quite low density compared to other fuels (liquid methane is 5x as dense) and is so cold you need a fancy tank with a lot of insulation to store it. The result is that the tanks are rather heavy compared to other fuels, which really eats into the efficiency.

Water is pretty dense so the tanks are small.

150:

In addition to the previous answers... The Falcon 9 also uses compressed gas (Nitrogen) as a rocket fuel for attitude control. That's the puffs of vapour you see shooting out of the top of the second stage as it lands. Hydrazine in the Dragon Two SuperDraco launch abort rocket motors and in the early versions of the Dragon as attitude control rockets (Draco). Something to start the main engines, I think it's Hydrazine too, but not sure, something hypergolic anyway. You'll see a flash as they start up which is the ignition fuel.


I just looked up a night launch. At T-0:03 you can see a flash of green that's the hypergolic (self igniting) rocket fuel running into the motor to start it off. I don't think it's hydrazine which burns yellow, so it's probably TEA-TEB

https://youtu.be/1lYZLxr3L4E?t=20m56s

You should really track down a copy of 'Ignition! An Informal History of Liquid Rocket Propellants' by John D. Clark ISBN 0-8135-0725-1

It's one of the most hilarious and interesting books I've ever read. Maybe the top of the stack.

151:

Just to add a few numbers, if you use Charlie's estimate of 3 kg of water per day, for a 4 month trip that's 360 kg of water per crewmember. For a crew of 7, that's 2.5 metric tons (sans storage tank).

To be worth it for a 4 month trip, your water recycler (with redundancy, spare parts, rack space, extra solar panels to run it, cabling, temporary water tank for outages, and so on) needs to mass less than 2.5 tons. Hopefully much less, since the tank of water is very reliable.

Based on the presentation slides, the ship itself masses 85 tons, carries 1,100 tons of methane and LOX, and 150 tons of cargo.

Of course, with larger crews on longer missions, it's easier to justify the recycler.

152:
You should really track down a copy of 'Ignition! An Informal History of Liquid Rocket Propellants' by John D. Clark

Seconded! This book is great.

153:

A taster for 'Ignition!' that gives some idea of the style of writing.

The next combination that the group tried then, was nitrogen tetroxide and methanol. Tests began in August 1937. But Malina, instead of working outdoors, as any sane man would have done, was so ill advised as to conduct his tests in the Mechanical Engineering building, which, on the occasion of a misfire, was filled with a mixture of methanol and N2O4 fumes. The latter, reacting with the oxygen and the moisture in the air, cleverly converted itself to nitric acid, which settled corrosively on all the expensive machinery in the building.
Malina's popularity with the establishment suffered a vertiginous drop, he and his apparatus and his accomplices were summarily thrown out of the building, and he was thereafter known as the head of the "suicide squad." Pioneers are seldom appreciated.

154:

You should really track down a copy of 'Ignition! An Informal History of Liquid Rocket Propellants' by John D. Clark ISBN 0-8135-0725-1

It's here: https://ia601905.us.archive.org/12/items/ignition_201612/ignition.pdf

I have no idea as to its legal status, but the book has been web-available since I downloaded it several years ago.

155:

if you use Charlie's estimate of 3 kg of water per day

In the US emergency/survival literature, 1 US gallon per person per day is the usual recommendation. 1 gal water -> 8 lb, so 3 kg looks in the ballpark. Probably depends a little on what the water is used for.

156:

Methalox has a bonus aside from being inexpensive, methane is much easier to handle then hydrogen, which can leak through almost anything.

157:

No-one's flown a methane-fuelled motor yet. I understand CH4/LOX has been tried by a few researchers and SpaceX has run a CH4/LOX motor on a test stand but if it was free from problems and better than RP as a fuel then it's likely that it would have been flown long before now.

The stories I've heard suggest the methane decomposes before combustion due to heat and pressure and there's also problems with sulphur contamination of the methane fuel plating out on the turbine pump blades and destroying them with imbalance. Not sure how accurate those stories are though.

158:

SpaceX isn't the only company betting on methane. Blue Origin & ULA are both planning on using the BE-4 methane (well, natural gas) engine for their new rockets, also in development.

My understanding is that besides the Isp boost, methane doesn't suffer from coking problems like kerosene does (in other words, it burns clean) and is suitable for advanced staged combustion designs.

I don't know all the details of the history, but a bit of quick research seemed to indicate that kerosene was chosen primarily because it was easy to handle and widely available. Liquefied methane on the other hand wasn't widely used in industry until more recently, and being cryogenic adds some problems.

One of the fun things about 'Ignition!' is that it explains a lot of the details about how military needs drove early rocket fuels development. In particular, for military use you really need a room-temperature fuel like kerosene or hydrazine.

159:

Re: YouTube video - night launch

Thanks - watched it. Very interesting combination of stage 1 (audio) and stage 2 (speed and telemetry values on upper right hand of the screen). Would be interesting to see graphs of fuel consumption for different stages, elevations, and speed.

Curious how they managed to film this.

160:

Re: 'Ignition! An Informal History of Liquid Rocket Propellants' by John D. Clark

With introduction by Isaac Asimov - irresistible! Look forward to reading this. Thanks!

161:

Re: Hydrazine

Had to look this up ... interesting chemical esp. that it can be manufactured in so many different ways in what looks like very few steps, is used in several industries, yet as per Wikipedia:

https://en.wikipedia.org/wiki/Hydrazine

'As of 2000, approximately 120,000 tons of hydrazine hydrate (corresponding to a 64% solution of hydrazine in water by weight) were manufactured worldwide per year.'

Seemed a very small quantity for such a potentially useful product until I read the hazards section. Never heard of a fuel that caused steatosis before.

162:

Hydrazine is a cuddly puppy compared to some of the crazy shit they tried. The entry on Chlorine trifluoride is a classic. With the line: It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water —with which it reacts explosively.

Who seriously considers an oxidiser that causes sand to burst into flame? Oh and the toxic effects of fluorine... OMG. Burn it with Hydrogen and get HF. The satanic god of horrid chemicals. https://web.utk.edu/~ehss/training/has.pdf

163:

Fair comment.

I have not yet had the pleasure of trying to get funds; I am hoping I never have too. No one (I hope!) goes into any type of science expecting to rich. That said, at least in theory, if not often in practice, in the engineering mentioned here there is the possibility however small to recreate, rebuild, or go around something.

Getting melodramatic here, but when it is trying to record a dying language, finding that one skull, or doing history with some palimpsest, there is often no replacement, no way to recreate, or find it again. Once lost, it's lost.

Which explains why some are a touch fanatical about record keeping.

164:

Hydrazine was used as part of the fuel for the Me 163. When I read on the Komet, I thought it was an interesting idea, until I read some of the details. Combustible pilots. That was crazy s***.

I like the bit about Chlorine trifluoride and fluoride metal fires in Wikipedia.

What I like to know is how anyone lived long enough to find, make, and do research on the stuff.

165:

Err ... NO
A Gallon of water weighs TEN pouns - one of the very useful "Metric" conversions which one can calculate in your head for BOFP calcualtions .....
2.24 lbs per kg, so 3 kg = 6.75 lbs (ish) Um.

166:

I once succeeded in making a VERY SMALL quantity of NCl3, whch was quite exiting enough, thank you very much. ( Drop conc liquid ammonia, drop-by-drop into a gas-jar full of Chlorine is the method )
At about 3-5 ml of oily liqid appearing at the bottom opf the gas-jar full of chlorine I was using, it spontaneoausly combusted/exploded, producing a double-needle flame, amost twice the size of the jar.

NI3 was much more fun, as you could make it in the school lab easily, mop it up onto filter paper ...
And then insert thin strips of same into a board-rubber ( As used by teaching staff to clean chalkboards )
If you did this the previous evening, it would dry out overnight, so that when the board-rubber was first used, it would burst into flames.

167:

As we have wandered on to the subject of rocket fuels it's probably a good point to mention that OGH wrote a story about that subject that tickled my funny bone.

https://www.tor.com/2012/07/20/a-tall-tail/

168:

Chemist David Lloyd's occasional blog on things he won't work with (because they will poison you, dissolve you, blow you up, or some combination of the three) - including the aptly named FOOF - has been mentioned here before
http://blogs.sciencemag.org/pipeline/archives/category/things-i-wont-work-with
The comments on them can be...interesting, too.

169:

*sigh* Derek Lowe, not David Lloyd.
I dunno, maybe I had V for Vendetta on my mind.

170:

"sulphur contamination of the methane fuel"

I think Elon has mentioned using the Sabatier process to make methane. So there should be no sulphur compounds in their methane. I don't know if sulphur came into his calculations, but he did say that it effectively made the rockets electric powered.

171:

The US gallon weighs 8 pounds. As did the original British gallon. The Imperial gallon and pint were changed in the 19th century to make the gallon 10 pounds. The Americans say, wrongly, "A pint's a pound the world around." Whereas we were taught "A pint of fresh water's a pound and a quarter.

172:

Basically the best fuel/oxidiser combo for a rocket is the most energetic one producing the most heat and the most mass thrown out the back of the very hot engine the quickest. The problem is that the "best" usually means most reactive in many ways hence the use of combos like N2O4 and Hydrazine which are nice and energetic but highly toxic, corrosive etc.

The Evulll! Shuttle flew with several tonnes of N2O4 and UDMH for manoeuvering purposes and eventual deorbit -- it could carry more than 18 tonnes in total if the tanks at the back of the vehicle well away from the passenger compartment were filled to capacity. (In contrast the Draco spam-in-a-can capsule design has N2O4/UDMH tanks for the landing rockets tucked neatly into the passenger spaces, and SpaceX has a history of leaky tankage...) If you watch videos of a Shuttle landing you'll see specialist defuelling teams in bunny suits at the back of the landed vehicle preparing to decant any remaining fuel and oxidiser to "safe" the Shuttle before it is transported off the runway.

The Cassini probe launched in 1997 was fuelled in flight by UDMH and N2O4. Half the all-up weight of the probe was fuel and oxidiser, in fact. The mix was useable to the last drop after flying in space for twenty years, one reason it's the goto fuel for long-duration missions where cryogenic tanks might well bleed out or where multiple engine firings are necessary.

173:

On board cameras transmitting to the ground stations under the track. Usually one at the top of the interstage looking down, one inside the interstage looking up, one either side of the second stage engine each looking diagonally across and down and one at the top of the second stage looking towards the payload. Dragon flights have a couple more on the outside of the Dragon, and there are camaeras inside some of the propellant tanks but apparently ITAR regulations won't allow those to be shown to the grubby public.

The ground cameras date from the Apollo era and are basically reasonable sized telescopes with very good operators keeping them aimed at the rocket.

For a daylight launch NROL-76 is interesting. Because it was a secret payload the coverage stayed with the first stage up and down.

174:

I seem to recall Clark mentions a proposal to use dimethyl mercury as a fuel.

That's the stuff that killed Professor Wetterhahn; it's pretty much the benchmark for neurotoxins, and it's pretty good at eroding aluminium as well (by amalgamation).

175:

What I like to know is how anyone lived long enough to find, make, and do research on the stuff.

During the 19th century there was an in-joke among chemists that you could tell when some eminent professor had isolated fluorine — all you had to do was follow the newspaper obituary columns.

176:

Greg, your gallons are not the same as their gallons.

177:

The smarter scientists working on fluorine used lab assistants. Lots of lab assistants.

178:

In another building

179:

Page 177

When he rings up, and asks a supplier to make 100 pounds of a substance so toxic that one drop on your gloved hand is certain death, it's hilarious.

180:

To be fair to spacex ref Draco vs the Shuttle - the can is so much smaller that it is hard to put anything a reasonable distance away from the Spam. You could fit 2 dragon 2 capsules in the length of the shuttle bay.

181:

I seem to recall not only that, but that some SF author chappie then riffed on it... :)

182:

Apollo had some problems with hydrazine, Apollo 15 landed on two parachutes instead of the normal three because the venting of the excess before landing dissolved some of the lines, and another crew landed up breathing some when the air vents to the outside opened before the hydrazine venting had finished.

183:

Electrolysis of ammonium chloride solution does it, too. Too much water in it to go off, though, and I didn't make any meaningful attempt to dry it out.

What I remember most about the stuff is the smell. I guess if you were using gaseous chlorine you'd not have been in a position to notice, but it's the kind of smell that gets right up your nose and stays there, and I could smell it for days afterwards.

184:

another crew landed up breathing some when the air vents to the outside opened before the hydrazine venting had finished.

Apollo-Soyuz Test Project, IIRC.

185:

That rocket was the Little Joe II
Bought the Estes kit version yesterday. Nice small winterproject for next year's launch season and I'm thinking of an upscale version for International Rocket Week in Scotland next august but it has competition from David Hardy's moon rocket which I also really like and want to build and fly.

186:

Once I'd realised it was a US poster, with inferior SMALLER "gallons" & - much more to the point - smaller PINTS (Ahem!), yes.
Good for a laugh, though ....

187:

Lab assistants who habitually wore red shirts.

188:

He specifically wrote US gallons.

189:

Re: A Tall Tale

Thanks! Good way to learn about real triple-threats (things that go bang, erode metals and poison you all in one) plus supporting evidence about just how bright some of the alphabet gang were/are.

Especially enjoyed the Operation Acoustic Kitty reference which involves training a cat with a surgically implanted mike to wander over to a park bench and hang around KGB agents. Would have been much easier, cheaper and more reliable to just wire the entire park (trees, benches, lamps) with mikes.

190:

Off-topic Q for USAians here.
Is Carmen Yulin Cruz, Mayor of San Jaun, Perto Rico, eligible to stand as POTUS?

191:

That, plus the need for a fuel that didn't freeze in really low temperatures. I think they got their best fuels down to something like -56 Fahrenheit.

For the deep space fuels the numbers below freezing were really interesting

192:

Obviously making LOX won't be a simple matter of waving a magician's wand, but try not to be so dismissive of what can be done. The Moon is cold enough to allow extremely low temperatures to be achieved. Liquification might be achieved by radiating heat during the lunar night. Is LOX on the Moon really harder than making methane and O2 on Mars and liquifying them?

193:

To reply to the top post. No. Just no. Trump doesn't have the vision and he's going to be dealing with Mueller soon. Ain't gonna happen. And we'll see how badly Puerto Rico impacts his presidency - rumor has it he didn't know that Puerto Ricans were U.S. citizens - and I suspect that things are worse there than we're being told.

On the subject of Pence... I wouldn't be surprised to see Pence take over after Trump is impeached, with the Fundies declaring that Trump's term in office was the prophesied reign of the anti-Christ, and now that Pence is here everything is perfect (in theological terms.) It's barely possible that God will want us to go to the Moon, but I kinda have my doubts.

194:

Good question. It all depends on the interpretation of the meaning of "...a resident "within the United States" for 14 years...". The territorial status of PR makes that requirement a bit ambiguous. OTOH, the GOP were willing to have Arnie run and he was naturalized, and Ted Cruz isn't a "natural born citizen" (was he decanted?) and he ran, so the rules can be bent or interpreted leniently.

195:

Charlie has commented on SABRE a few times in previous blog posts. Looks like they're serious or at least have gotten more funding.

https://en.wikipedia.org/wiki/SABRE_(rocket_engine)

Wikipedia entry:

'In September 2016, agents acting on behalf of Reaction Engines applied for planning consent to build a rocket engine test facility at the site of the former Rocket Propulsion Establishment in Westcott, UK[30] which was granted in April 2017,[31] and in May 2017 a groundbreaking ceremony was held to announce the beginning of construction of the SABRE TF1 engine test facility, expected to become active in 2020.[32][33]'

Reads like a Laundry backgrounder: things that go boom tend to get located on the same geographic spot. Coincidence?

Anyways the Wikipedia description sounds very attractive. Basically, has a bunch of things that I've wondered 'why don't they ...'.

196:

Deep space fuels can be kept liquid with a few watts of electrical heating in the tanks assuming solar input is insufficient. What puzzles me, although I assume Great Minds have already solved this problem is that I understand Musk's Mars rockets plan to use LOX as an oxidiser and keeping the LOX cold over a period of months of exposure to 800-900W/sq metre insolation en route is gonna be tricky. Active cooling of the tanks would require kilowatts or more of electrical power plus heat exchangers, radiators, backup systems etc. After a while something like N2O4/UDMH starts to look like a better bet logistics-wise even if the Isp is a bit lower.

197:

LOX (and methane) can be kept cold in deep space simply by using a sunshield and perhaps a bit of insulation.

In case this seems weird, look at the James Webb Space Telescope: the plan there is to use a rather good sun shield to cool the business side of the telescope down to 50 K, which is comfortably cold enough. Or rather too cold: the LOX would freeze solid.

The problem is actually much harder in low Earth orbit, because then you have to deal with both the sun and the Earth cooking your space ship, often on both sides at once. The JWST solves this issue by orbiting a Lagrange point.

198:

To expand on Alex Tolley's answer above, as she was born in Puerto Rico she's a natural born citizen and thus eligible. The only sticking point is that there's also a requirement that the president have "been fourteen Years a Resident within the United States."

Does a US territory count? Who knows.

199:

the ordinary smartphone is has replaced whole buildings full of IBM computers, so there's got to have been similar mass/weight savings in space capsule tech. If not - then this is a problem area that should be addressed.

Well, in Apollo most of the computing was done on the ground, by those aforementioned buildings of computers (and people with slide rules.) A quick look shows the Apollo Guidance Computer weighed 32 kg, so you could save a substantial portion of that with more modern hardware. Probably not off-the-shelf, though, due to flight safety requirements. There would be some savings in radios, replacing flight instruments with flat panels, etc, but the need for redundancy and hardening probably means it won't be as dramatic as you'd think. Avionics are bulky and heavy compared to what you expect in consumer electronics.

200:

The spaceship has small tanks inside the main tanks for storing the descent propellants. That also isolates them from the outer walls and makes it easier to keep both the oxygen and methane cold.

201:

Re: 'Does a US territory count? Who knows'

According to this site, yes, it does.

https://www.usconstitution.net/consttop_citi.html

'Separate sections handle territories that the United States has acquired over time, such as Puerto Rico (8 USC 1402), Alaska (8 USC 1404), Hawaii (8 USC 1405), the U.S. Virgin Islands (8 USC 1406), and Guam (8 USC 1407). Each of these sections confer citizenship on persons living in these territories as of a certain date, and usually confer natural-born status on persons born in those territories after that date. For example, for Puerto Rico, all persons born in Puerto Rico between April 11, 1899, and January 12, 1941, are automatically conferred citizenship as of the date the law was signed by the President (June 27, 1952). Additionally, all persons born in Puerto Rico on or after January 13, 1941, are natural-born citizens of the United States. Note that because of when the law was passed, for some, the natural-born status was retroactive.'


So Carmen Yulin Cruz, Mayor of San Juan, Puerto Rico, is eligible to stand as POTUS. And, she's not some backwards country hick either: education - Boston U, Carnegie Mellon U; work - Westinghouse, Colgate-Palmolive, Banco Popular, Cellular One (now AT&T), Scotiabank, and the United States Treasury Department. The 'natural-born' thing should be a non-issue given that McCain was the GOP's 2008 POTUS candidate.

'In 2008, when Arizona Senator John McCain ran for president on the Republican ticket, some theorized that because McCain was born in the Canal Zone, he was not actually qualified to be president. However, it should be noted that section 1403 was written to apply to a small group of people to whom section 1401 did not apply. McCain is a natural-born citizen under 8 USC 1401(c): "a person born outside of the United States and its outlying possessions of parents both of whom are citizens of the United States and one of whom has had a residence in the United States or one of its outlying possessions, prior to the birth of such person." Not everyone agrees that this section includes McCain — but absent a court ruling either way, we must presume citizenship.'

202:

Oh, good, in fact: DOUBLEPLUSGOOD!
Because, I could see her running against DT in 2020 (assuming he's not in jail), or even running against Pence.
The Usual Suspects will, of course try a re-run of the "Obummer is a Kenyan" shite, but I think she could eat the Repubs alive, given the right publicity ...

203:

Please read a little closer. Both Alex Tolley and I were mentioning the vague residency requirement, not the citizenship requirement. She's clearly a citizen.

I would guess that she's 100% eligible, and if she were to run this would in no way protect her from an insane uprising of fact-free racists screaming that she's not in a frenzy hateful invective on every unmoderated internet forum they can find.

204:

Re: Residency

Believe that residency is implicit in the 'natural-born'.

205:

Re: Residency


(Hit the button too soon ...)

That is, she's lived in Puerto Rico or the mainland for most if not all her life*. If having been born in Puerto Rico is good enough to claim natural-born status, then it follows that living in Puerto Rico should also count as living in the US. Lawyers and racists can and will say anything. What decides though is what SCOTUS says based on current law. As for amendments from the GOP-controlled Congress and Senate: Yes, also possible but it's usually harder to repeal human rights than to grant them.

*The Wikipedia entry doesn't identify her specific office location re: the US-based orgs she's worked for.

Wonder what it would take for Hispanic MLB (US baseball) players to boycott the US teams. Can't imagine what that would do to the national pastime.

206:
Believe that residency is implicit in the 'natural-born'.

It's not. They're clearly separate requirements, e.g. if you were born in New York but lived your whole life in France. Also, you can be a citizen because your parent(s) were citizens, and according to this summary, lawyers still seem to argue about whether it counts as 'natural-born'.

207:

When are we going to see any really good movie adaptations? I thought the adaptation of 'Do Androids Dream of Electric Sheep' was good, albeit not much like the original. Beyond that I struggle to think of any good adaptations. Some like 'I, Robot' were like horrid mirror image negatives, exactly reversing the message of the originals. Most are just a boring series of jack-in-the-box 'scares' and explosions.

Don't get me started on what a complete travesty they made of Heinlein's Starship Troopers!

208:

It was a pisstake, which is about as good as Heinlein deserves.

209:

Not sure I agree with that - thematically it was similar. Both deeply satirical. A plot that bore a passing resemblance to chunks of the book.

There have been quite a few good adaptations - most recently The Martian and the Hunger Games spring to mind.

Enders Game is fairly recent but only middling imo.

It does depend on how you define good - just a good film in its own right or a faithful adaptation too?

Good list here although it's missing 2001.

https://en.m.wikipedia.org/wiki/Category:Films_based_on_science_fiction_novels

The film of the Three Body Problem appears to be due for release imminently.

210:

I have no idea as to its legal status, but the book has been web-available since I downloaded it several years ago.

The icon that appears on the tab when I open the URL is the Old Well at at the University of North Carolina, which suggests the file is hosted at Ibiblio, which in turn suggests it's been donated to the world for educational purposes. It should be there, free for non-commercial use, for as long as UNC exists.

211:

Err ... NO
A Gallon of water weighs TEN pouns - one of the very useful "Metric" conversions which one can calculate in your head for BOFP calcualtions .....
2.24 lbs per kg, so 3 kg = 6.75 lbs (ish) Um.

Imperial gallons maybe, a U.S. gallon (of water at 39°F) weighs 8.34 lbs (3.725 kg).

212:

Off-topic Q for USAians here.
Is Carmen Yulin Cruz, Mayor of San Jaun, Perto Rico, eligible to stand as POTUS?

According to Wikipedia, Puerto Ricans are natural-born citizens of the U.S. She was born in Puerto Rico in 1963, so she should qualify.

The question usually comes up when a candidate is born to U.S. parents who are outside the U.S. at the time the child is born ... George Romney in 1968 (Mitt's daddy, born in a Mexican Mormon Colony in 1907) and John McCain in 2008 (born in a U.S. Navy hospital in the Panama Canal Zone in 1936).

Moot in the case of Obama in 2008 & 2012 because Hawaii was already a state when he was born there in 1961

213:

Good question. It all depends on the interpretation of the meaning of "...a resident "within the United States" for 14 years...". The territorial status of PR makes that requirement a bit ambiguous. OTOH, the GOP were willing to have Arnie run and he was naturalized, and Ted Cruz isn't a "natural born citizen" (was he decanted?) and he ran, so the rules can be bent or interpreted leniently.

I forgot about the "14 years a resident" part. Most likely, it means she would have to move to one of the 50 states and wait. If she moved this year, she would be eligible to run in 2032.

Arnie wouldn't be eligible without a Constitutional Amendment.

Article 1, Section 2, Paragraph 8 says Congress has the power to "establish an uniform Rule of Naturalization". Since the 1st Congress in 1793, children of U.S. citizens born abroad have been considered "natural-born" citizens. Ted Cruz, however despicable, falls within that category.

214:

Before writing off high-thrust ion drives, buy increasing the power to run multiple engines you can get much more thrust and short travel times. The problem is the power supply. Those nice solar arrays have too low a power density. However, that is not fixed forever. Thinner panels and concentrators made of thin films could increase the overall power density.

My calculations suggest that by increasing the power density by about 10x, and using the Dawn mission craft as a baseline, you could accelerate/decelerate to the cumulative 10 km/s delta V in just 3 days, with larger, higher power density arrays and doubling the xenon propellant load. (All calculations assume travel at 1 AU, not to the asteroids.)

If those calculations are correct, then ion engines would be fine for crewed interplanetary travel. Still not great for the Earth-Moon run, unless you applied even more juice and/or reduced the Isp, a trade-off likely possible to reduce travel times compared to using chemical engines. Bear in mind that for the Earth-Moon run, power beaming is quite doable too, with a high power microwave emitter whose beam is converted to electricity by a lightweight rectenna might well be a good solution here. I suspect that chemical rockets would still be the best choice for the touchdown.

My guess is that these approaches will be used on CubeSats and other privately owned craft as the cost of experimentation is low and doesn't require the Nasa TRL 6 before flying a mission.

215:

Re: Birth vs. residency

Read some more about this elsewhere and it seems this question is still in the air - tossed back and forth like a hot potato between judiciary and legislators.

Recall a WW2 story about the Dutch royals who escaped to Canada shortly after the Nazis occupied the Netherlands. One of their daughters was born in an Ottawa hospital during the war but thanks to some diplomatic/legal footwork her birthplace was made 'not-Canada' so that she would not automatically be considered a Canadian (as per Canadian law) and would take on only her mother's nationality (as per Dutch law).

Other well-known places and situations that are legally considered as being that particular country and that have nothing to do with geography, i.e., embassies, ships, and planes.

216:

Just replace all our concrete structures with diamond bricks...
What's not to like?

How would you demolish it?

Serious problem, in the long term.

Now I want to read a story about this - indestructible buildings accumulating over the centuries, layering up on top (and under) each other, because you can't get rid of the damn things. The Parthenon still stands, shame about the bits the Huns added in the 6th century, and stuff the local added in the 1920s to make the 1600s minarets not look like minarets.... as for the Berlin Wall, just don't ask, it's looking like another London Wall debacle.

Pave the planet!


Me, I'm just trying to remove a 1920s concrete and brick garage that's too small to hold a modern car (a Model T fit snugly), and too dark and badly located to be a decent bike shed. It is surprisingly bloody expensive.

217:

Seemed a very small quantity for such a potentially useful product until I read the hazards section. Never heard of a fuel that caused steatosis before.

And harking back to comments about shuttle costs here the Wikipedia entry about what got to happen after a shuttle landed. Something like 20 tandem trailer trucks plus smaller vehicles going down the runway behind the shuttle as it landed. (Which basically says those abort runways around the world were likely to be final resting places if ever used.)

https://en.wikipedia.org/wiki/Space_Shuttle

After landing, the vehicle stayed on the runway for several hours for the orbiter to cool. Teams at the front and rear of the orbiter tested for presence of hydrogen, hydrazine, monomethylhydrazine, nitrogen tetroxide and ammonia (fuels and by-products of the reaction control system and the orbiter's three APUs). If hydrogen was detected, an emergency would be declared, the orbiter powered down and teams would evacuate the area. A convoy of 25 specially designed vehicles and 150 trained engineers and technicians approached the orbiter. Purge and vent lines were attached to remove toxic gases from fuel lines and the cargo bay about 45–60 minutes after landing. A flight surgeon boarded the orbiter for initial medical checks of the crew before disembarking.

Final point. Picking a fuel is really about picking an entire system/process.

218:

Obviously making LOX won't be a simple matter of waving a magician's wand, but try not to be so dismissive of what can be done.

Making it is only part of the issue. Storage. Plumbing. Fueling. (How close to the pump do you try and land and unless a few meters how to you deal with the hose? How long does it take to make up a "fill up" worth of LOX.

And do you really automate all of this or keep a gas/petrol station crew on the moon?

So I give you enough magic to fill a tank with LOX but how about the rest of the system to make it all work?

219:

Does a US territory count? Who knows.

Quick do a search for any presidents who lived in the territories after the original 13 states.

220:

Re: 'Serious problem, in the long term'

Not necessarily - doesn't matter what the building blocks are made of, it's how these building bits and pieces are sized, shaped and held together. Modular assembly à la Lego makes sense wherever there's a potential materials shortage.

Recall in one of the BBC Time Team episodes where the archeologists determined that some of the masonry and oak beams in one structure had been sourced from one or more previous structures.

221:

Yes. But 10 pounds per gallon is useful when calculating how much is takes to haul around a gallon. That extra bit fudges the container. :)

222:

It is surprisingly bloody expensive.

Makes you pause when you swing the 10 pound sledge and the only result is a few chips.

223:

Re: 'Final point. Picking a fuel is really about picking an entire system/process.'

Agree - and now to nitpick about what defines the best system/ecology which is very much subject to fashion, whim and corporate tax law and liability. Just think of how for-profit megacorps changed in the past 100 years from total vertical and horizontal integration (automotive and consumer packaged goods and foods) to zero tangible physical assets, production or design (shale oil - they only hold/own contracts/rights).

224:

diamond bricks... How would you demolish it?

With a gas axe or plasma cutter if all else failed. Diamond burns, just not well at 20% oxygen. Heat it up a bit and spray oxygen on it and it should cut like steel does.

But I expect that few pieces would be custom made, it would be more sensible to have 90% of the parts standardised and quite a lot more like Lego than you might initially suspect. With vertical ties to stop it falling apart diamond could be a really good way to push past "standard bricks" and into "standard, reusable everything".

Solid diamond would be really annoying though, because it conducts heat and lets in/out light. You'd probably find that a more typical building material with solid/foam/solid worked better, and knowing the way architects and councils work, the outer surface would need to be rough so it could be rendered or painted. Then there's the ugliness of being in a room with very hard, flat surfaces, so you'd likely find that wallpaper came back into vogue. Thick, velvety wallpaper.

Also, don't bitch about taking apart buildings until you'd dealt with the aftermath of people who like to concrete asbestos sheeting into place. It cost $AU3500 to have the cladding taken off our single garage and that was as simple a job as you can imagine. Getting corrugated sheeting garden beds and fences taken away is a nightmare, because breaking up concrete without breaking up the more fragile asbestos sheeting can't be done. But if you wash away the asbestos fibres as they break apart, you've just created a reservoir of asbestos dust when it dries out. So you enclose the whole fence/garden in a big plastic tent and people in space suits chisel it all apart, each accompanied by their vacuum-wielding assistant. It costs as much as you would expect. Then you have to pay to have everything entombed, and they charge by the cubic metre. If you can at all avoid it, just don't buy an asbestos house (in Australia, that rules out the 1945-1980 period unless you're very, very lucky)

225:
My calculations suggest that by increasing the power density by about 10x, and using the Dawn mission craft as a baseline, you could accelerate/decelerate to the cumulative 10 km/s delta V in just 3 days

Could you explain your calculations?

I just looked it up, and the NSTAR thruster used on Dawn masses around 25 kg. It produces 92 mN thrust at 2.3 kW.

At 92 mN, the engine would take over 30 days to accelerate its own mass to 10 km/s, much less the mass of the space ship attached to it.

Now, maybe we can make ion drives that mass nothing, so let's consider just the power aspect. Wikipedia claims that ion thrusters are already rather efficient (65-80%) so no real improvement here. The thruster thus requires about 25 kW per Newton of thrust produced. If we turn this around to your 10 km/s in 3 days figure, then my calculation is that you need about 1 N for every 26 kg of ship (ignoring the propellant mass), or close to a nice round 1 kW per kg of ship. At Mars, that's close to 10 square meters of solar panel per kg of ship, just for power. Or about 1,000 m2 per person.

226:

With a SciFi TV show playing in the background the big honking space ship descends into the atmosphere and lands on another planet without a space port.

Between my wife and I we average more than one round trip airplane flight per week. About 1 in 10 of those get stuck for a maintenance issue. And there are likely a lot more we don't know about as they are fixed/cleared during the ground turnaround. Most of the ones we do become aware of were quickly fixed but not everyone got the paper work signed before dor closure time. And I suspect there's a lot of must be fixed but can wait till tonight done overnight.

Anyway within a big SWAG[1] modern passenger jets are about as complicated as a lunar fuel station. And they need constant maintenance by shaved apes to keep operating. Just who keeps this lunar LOX station operating. Say the LOX station needs only 1/10 of the maintenance of a plane. That's still a lot of work.

[1] https://en.wikipedia.org/wiki/Scientific_wild-ass_guess

227:

Storage is easy, we know how to do that. You don't run hoses, but rather fill a smaller container truck, drive over to the ship and pump into the tanks, just as we manage jet fuel with aircraft at airports, or rockets at launch pads. The rovers can be manned or robotic/teleoperated by the ship's crew. No magic, just basic operations adapted to the Moon. Sure, there are issues with lunar dust, but let's not make these obstacles into a showstopper, as they can be engineered around.

228:

I assumed no mass for the engines, just the mass of the arrays with an assumed power density that could be raised 10x. MIT has demonstrated super-thin film arrays in the lab at 6W/g, I think it is not unreasonable to believe that very high power density arrays based on a sail and boom designs might offer the power densities needed for electric propulsion. Yes, the arrays will be large, but not as large as equivalent solar sails, and we have many designs for very large sails. I think we may get there from here, obsoleting chemical rockets for high delta-v spaceflight propulsion at least for inner system travel. For outer system travel, beamed power from lasers might be the path to go, especially if Breakthrough Starshot stimulates the development of Lubin's DSTAR high-powered laser arrays. Nuclear power is fine too if it can be developed.

I will work some more calculations to see what may be achieved.

229:
I assumed no mass for the engines, just the mass of the arrays

Besides massless engines being somewhat optimistic, ion drives still use propellant.

By the rocket equation Δv = ve ln (m0/m1), with an exhaust velocity of 31 km/s, we need 39 kg of propellant for every 100 kg of spaceship, or 28% of the ship's mass, to achieve 10 km/s Δv. That's a lot better than the 93% a chemical rocket might use, but it does represent two years of the world supply of Xenon... perhaps a cheaper element would be better. It also makes the size of your array more complicated.

A second problem is that ion drive thrust is limited by areal density: to put it simply, you can only put so many ions in an area of space before you get sparks. As I understand it, the physical implication of this is that you simply can't have a compact ion super-rocket that will happily consume a gigawatt of power -- instead, the rear end of your ship ends up being rather large and loosely packed with many small drive units. I wasn't able to find a reference for exactly how diffuse, but this all implies a fair bit of structure and cabling, not a lightweight thruster.

230:

but it does represent two years of the world supply of Xenon

... for a SpaceX BFR size space ship, that is.

232:

Between the bricks is mortar/cement/joining substance - "softer" than diamond.
NOT a problem .....

233:

That rocket was the Little Joe II. Bought the Estes kit version yesterday.

Congratulations, I hope it flies better than the original!

Thank you, and thanks to Elladan for the video. It's cool to see what I only vaguely remembered (and to find out I got all important details right after so long).

234:

"SWAG" - isn't this just a n other vesion of "BOFP"?
[ Back-of-Fag-Packet ( Calculation) ]

235:

Off-topic Q for USAians here. Is Carmen Yulin Cruz, Mayor of San Jaun, Perto Rico, eligible to stand as POTUS?

So far as I can tell, yes. She is of age (born 1963), was born in the United States (in San Juan, Puerto Rico). and has been resident in the US for over 14 years (Massachusetts and Puerto Rico).

236:

I will note that Carmen Yulin Cruz is the mayor of city of 400,000 people. In terms of number of residents and authority that's roughly equivalent to the governor of Alaska, although she seems to be doing a better job than Sarah Palin ...

Until 2008 she'd have been way too short on political experience to be a credible running mate for a candidate, never mind a contender for the top table: no state level experience, let alone Congressional/Senate seat.

Yes, she's someone to keep an eye on — but unless you believe Trump has permanently disrupted the traditional markers for executive office in the US, she's too inexperienced.

On the other hand? If we wake up in 2018 and find she's in congress/senate, representing [a newly turned Democrat] Florida, then yeah, she might be in the running.

237:

ust replace all our concrete structures with diamond bricks... What's not to like?

How would you demolish it?

Well, presumably bricks are held together by mortar (glue), or bolts. So that's the weak spot: unscrew the bricks, abrade/dissolve the glue, and recycle them. And if any of them are badly damaged, burn them. (Furnace, brick, bucket of liquid oxygen, be sure to stand well back.) Regular bricks are pretty much non-inflammable. Diamond bricks ... diamond oxidizes in air if heated above 700 celsius, at which point you get CO2, so it loses structural integrity as a construction material at about the same temperature as steel. Presumably same insulation requirements apply, with the added twist that where steel melts, carbon burns.

238:

It may be spam to you, but some of us are just sick of having an organ and are desperate to find someone who will take it away.

http://www.antipope.org/charlie/blog-static/2017/05/rejection-letter.html#comment-2035419

239:

British or US gallon? They're different sizes. Well, both are 8 pints, but the US pint is 16 fl. oz, and the UK pint is 20 fl. oz (I think the fluid ounces are close enough that we can ignore that).

240:

I recall a presentation at a conference some years ago on the development of indium ion thrusters with an Isp around 12,000. The point being they could be manufactured by semiconductor-like lithographic processes and the bulk fuel is a metallic solid until you switch on the current.

If you combine such a thruster design with the photovoltaic panels, so that you have an array of microthrusters printed on the solar array "sail", you could end up with a disposable "thrust unit" that you dump (or send on a long return orbit for recycling) after it runs out of fuel, and where the ion thrusters and their fuel are part of the structural mass of the solar panel that powers them.

This is kind of speculative and may be inefficient (lots of redundant power management hardware to turn the output of PV cells into the HV needed to power small thrusters) but has a certain elegance insofar as sails could be "tailored", quite literally, to specific missions.

241:

THAT was the whole point of my reply ...
Especially if you are interested in drinking certain liquids in Pint quantities .....

242:

Tanenbaum's Law is to 'Never underestimate the bandwidth of physical media hurled fast enough' [originally: "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway."]

See also.

243:

Sorry to reply to two of your comments in a row, but have you seen the back of a cigarette pack recently? Shiny glossy plastic wrapped photos of gruesome medical conditions caused by smoking; i'm curious what they used to look like that you could scrawl on them?

244:

Vague memories of my grandfathers Players Navy Cut packets, the back just had the sailor logo in colour, but scribblings usually involved opening the empty pack out flat and using the inside.

245:

Since we're on the topic of Carmen Yulin-Cruz (CYC), the right wing has already begun to demonize her.

From the Guardian,
"In 2016 she dedicated her election win to Oscar López Rivera, a controversial figure in Puerto Rican politics, and a former member of a radical Puerto Rican independence group that committed several terrorist attacks on the mainland during the 1970s."

https://www.theguardian.com/world/2017/oct/01/carmen-yulin-cruz-mayor-puerto-rico-donald-trump

The right wing is already calling her a terrorist sympathizer.
http://dailycaller.com/2017/09/30/san-juan-mayor-praised-convicted-faln-terrorist/

As I've said in a previous thread, the right wing has learned from Katrina: criticize the nearest Democratic officials. Already, the right wing is spreading rumors that

1. The teamster union has gone on strike and refuses to move aid
https://www.theepochtimes.com/puerto-rico-union-allegedly-refuses-to-deliver-us-aid-on-strike-because-of-local-law_2324073.html

2. CYC refuses to deliver aid to make Republicans look bad.
https://www.youtube.com/watch?v=_3-2SfCijdc

246:

Indium ion micro thrusters.

Yes, Isp of 10,000+s was measured

paper:
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1997ESASP.398..267R&db_key=AST&page_ind=0&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES


Nasa news report on printed approach:
https://microdevices.jpl.nasa.gov/capabilities/advanced-microfabrication-technologies/microfluidic-electrospray-propulsion.php

These look more suitable for tiny satellites and position keeping, but they may well offer scale-up opportunities.

247:

Ah, the spell casters. I get to see them in waves every now and then on a blog where I deal with the SPAM.

Queen for a day stories where the spell caster cures all the problems at some point.

248:

Re: Spammers

Wonder if it's someone who read Charlie's comment about intentionally keeping this blog free of tech doodads (therefore less susceptible to spam) and decided to let their inner brat out and challenge.

250:

If you see spam in the comments would you mind saying so?

One of the mods deleted it before I saw it, so it took me a while to go searching, locate the spammer account, ban them ... and dig up the other spams they'd posted elsewhere that nobody noticed.

251:

Okay, will do since I occasionally look at previous topics.

252:

I only saw it as it was put on a older post but happened to be the first comment in the side bar of the Diary screen. And I happened to go there to see if there were new comments.

253:

Well, we can start with the old piece from the seventies(?), about comments considered hazardous (all the fumes from the printer ink).

We can go on to "if it was hard to write, it should be hard to read".

Then we can hit reality: in the mid-eighties, where I was working had one (1) systems programmer for the mainframe. He took a week's vacation... and somehow they found him, on Tuesday, on the beach, and dragged him back. A month later, the lead operator was promoted to assistant systems programmer.

Moral: if you want a life, and if your organization has any worry that you might change jobs, or get hit by a car, etc, realize that "never let them know what you're doing" is NOT a great job security plan.

Note: about writing documentation, allow me to offer my published article on it: http://24.5-cent.us/egoless_docu.html on how to write documentation that people are actually willing to use....

254:

Re: I, Robot: or, as many of us referred to it, "Based on a collection of short stories of that name by Isaac Asimov, and with several characters with the same names as people in the stories".

255:

I disagree. Nixon and the GOP felt that it was a Democratic Party triumph, and they had no interest in it, since there was no "real" money to be made out of it.

Carter did go with Apollo-Soyuz, and I believe that if he'd beaten Raygun, we would have seen more joint projects.

256:

A late friend of mine told me, long ago, how he'd made ammonium chlorite(?), then put small amounts all over his mom's kitchen floor, and let it dry. Much amusement (his) followed when she walked across the floor.

257:

Safe sources of methane... I can see cattle, with tubes attached to their butts, towing a small cylinder on wheels, and thus reducing methane emissions....

258:

Astronauts regularly carry hardened laptops onboard. "Hardened", meaning, last time I read this, was either a 386 or a 486 processor, since smaller lithograph CPUs are more vulnerable to radiation.

259:

If you see spam in the comments would you mind saying so?

One of the mods deleted it before I saw it, so it took me a while to go searching, locate the spammer account, ban them ... and dig up the other spams they'd posted elsewhere that nobody noticed.

The World of Tomorrow comments #609 through #625
Rejection Letter comments #711 through #716

Still there as I'm reading this afternoon (2 Oct - USA EDT)

260:

Is "programming dad" a typo, or a piece of jargon I'm not familiar with?

261:

Some types such as Embassy and Regal used to have fairly large areas of unprinted white on them. Others such as B&H were mostly a uniform light colour and were also good for scribbling on, if you could get the pen to start that is.

Beermats are also useful for impromptu design calculations; usually the printed surface will peel off in a thin layer exposing a usefully writable-on white surface beneath.

262:

I'm betting it is a typo for "fad".

263:

So this 0.9 draft needs a revision?

264:

Quick do a search for any presidents who lived in the territories after the original 13 states.

There have been several candidates born either to US citizen parents overseas or born in US possessions or territories, but none have won election to the presidency.

Abraham Lincoln (b.1809) was the first president born in a state that was not one of the original 13 colonies. Kentucky became a state in 1792 before Lincoln was born.

John Tyler was the only President of the United States to have subsequently held office in the Confederacy, serving in the provisional Confederate Congress. He was elected to the Confederate House of Representatives in November of 1861, but died before their first session convened in February 1862.

Harry S. Truman was the first president born west of the Mississippi.

Richard Nixon was the first president born on the west coast of the US.

Barry Goldwater (b.1909) is the only one I can think of who was born in a US Territory before it later became a state (Arizona, 1912).

265:

Correction: Herbert Hoover was the first president born west of the Mississippi; in Iowa.

Other interesting factoids ...

After Lincoln, the next seven presidents not born in one of the original 13 states, were all born in Ohio (Grant, Hayes, Garfield, Harrison, McKinley, Taft, and Harding).

Coolidge, born in Vermont, was the first president not born in one of the original 13 states who was not from Ohio. Vermont was an independent republic when it became the first state admitted after the original 13.

Since Coolidge, no president has been born in Ohio.

266:
Musk's system bypasses the whole Isp issue by being based on in-flight refueling. If you start in LEO with full tanks and 7km/s Δv, there really are transits to Mars that are only 3 months, which is much faster than you can achieve with any reasonable ion drive based system.

You still need to get all that fuel into space in the first place though, right?

Exhaust velocity of a hydrogen/oxygen rocket is about 3km/s, or thereabouts; that means to get a delta-v of 7km/s you need a mass ratio of a bit over 10, and your surface-to-orbit system will be lucky to get a mass ratio of 20, so you'll need to make a lot of flights to even get fuelled up (or you take a miniscule payload, and that won't work if you're sending people). Brute force might work, but its going to cost a hell of a lot.

A deep space only ship is also not really as useful as it sounds at first. Primarily, you really want to be able to use aerobraking for Earth and Mars. Complexity wise it really doesn't hurt if your ship can actually land on those planets, too.

I know there are various colors and flavors of design of inflatable heatshields for aerobraking (I haven't checked to see if any have actually been tested, mind you), but if you're going to go all brute-force on the problem you could just bolt a couple of nested aeroshells to the spacecraft and throw em away after they've been used, no? On the return flight, you could just bin most of the ship; only a little bit needs to survive re-entry after all. Deep space doesn't mean it has to be re-useable, right?

267:

Barry Goldwater (b.1909) is the only one I can think of who was born in a US Territory before it later became a state (Arizona, 1912).

So was my mom: http://genealogy.az.gov/azbirth/408/408-0799.pdf

And my father was born on a US commercial concession in Aguascalientes, records thereof having been lost in a subsequent political event.

I'd probably never have made it as a POTUS candidate.

268:
My calculations suggest that by increasing the power density by about 10x, and using the Dawn mission craft as a baseline, you could accelerate/decelerate to the cumulative 10 km/s delta V in just 3 days, with larger, higher power density arrays and doubling the xenon propellant load.

How certain are you of those figures? I was under the impression that if you crank up the power of an ion drive too far without increasing fuel flow you get arcing, and if you try to just push more fuel through the nozzle you end up choking the flow by the fact that you're trying to fire charged particles into a big blob of like charge.

I don't doubt that there's some of headroom above current state-of-the-art ion drives, but I'd be surprised if there was as much as you're suggesting (as would a lot of plasma thruster people, I suspect).

269:

Expected propellant mass for the spaceship is 1100 tons for a full load, payload to LEO is 150 tons so 7 tanker trips needed to top off the ship in orbit.

270:

I'd probably never have made it as a POTUS candidate.

Under U.S. law in effect when your mom was born she was a citizen both "by blood" & "by soil". Her parents were both U.S. citizens and she was born in a U.S Territory. You would be a citizen "by blood" from your mom even if you were born outside of the U.S. or it's territories.

You might not be a viable POTUS candidate for any number of reasons, but if you're at least 35 years old, you are eligible to hold that office by birth-right (assuming you haven't been expat for the last 14 years).

271:

There is a major bootstrap operation that is probably essential for serious space travel to be a realistic proposition but unfortunately it requires a lot of investment and a very long period before it starts making a profit. That is space-based fuel production and distribution.

At the moment to go anywhere in our system everything needs to be lifted out of our gravity well at $5000 a kilo by spending reaction mass at a ratio of 50:1 or more. Even partially-reuseable rockets have a functional overhead in terms of reserved landing fuel and landing systems which cut into payload to orbit so increasing the number of flights needed per kilotonne of supplies in LEO.

A robotic fuel production system set up to mine ice asteroids or Saturn's rings and deliver the resulting water to Earth orbit would save a lot of launches and make going anywhere from LEO into the Solar System a lot cheaper but it would cost trillions to build out and take decades to get into operation before the first production tankerload of processed water-ice arrived in LEO. The only good thing is that the second tankerload arriving a few months later would be a lot cheaper.

272:

Yes,

Rather worried night at this end, family attending a conference in LV. Couldn't get in contact with them for about 6 hours after the shooting. Fortunately they slept through the whole thing.

273:

I have this idea that Saturn's rings sit in a deeper gravity well than Earth.

I can't find figures, but XKCD looked at this.

https://xkcd.com/681_large/

Fuel from the Moon, yeah (particularly with a rotovator). Fuel from Saturn... I can't see it.

274:

You have my curiosity up.

Which rebreather(s) did you work on?

(Full Disclosure: I did a pool dive on Peter Ready's PRISM prototype, several years ago, when they were letting lots of people dive it, so they could find out what needed to be beefed up.)

275:

The problem with taking off from Earth is that the thrust has to be more than 1g since the vehicle has to reach orbital velocity before the fuel runs out. Getting out of Saturn's rings can be done with a lot less thrust, much less than the local gravity field since the tanker/refinery is already in orbit around the gravity well. The fuel is free in terms of gravity and there's no real time limit if it's a pipeline operation with unmanned tankers departing from Saturn orbit every few weeks or months.

The return trip to LEO and getting the nearly-empty tankers back to Saturn will take years, possibly with slingshot assists around Earth and Venus similar to the Cassini probe flight profile but that's part of the big time investment in the project before any sort of return will accrue.

If water ice or other fuel material could be sourced from, say, the Moon then that would be quicker and more convenient but ice is easy and we know where there are large amounts of it even if it is farther away. I know folks are working on an ion-engine system that can run on aluminium scrap but that's early days. Harvesting dead geosync satellites for their metals and solar panels could yet become a viable business...

276:
You still need to get all that fuel into space in the first place though, right?

Yes. I imagine their mission profile looks something like this:

Launch 1: Tanker #1 flies to LEO and parks.
Launch 2-5: Tanker #2 shuttles back and forth to LEO and tops up Tanker #1 until it's full.
Launch 6: Mars ship flies to LEO, fills its tanks, and heads out to Mars.

(Not sure about the exact number of launches)

The whole economic idea underlying their plans is that the ship is going to really be fully reusable, in the way people envisioned the Shuttle would be early on. That is, basically airliner style: just gas and go, with scheduled maintenance.

The actual propellant to fill one of these things up isn't very expensive, maybe less than $1M. If the ship really was reusable, the whole fueling campaign would cost much less than a satellite launch costs now.

Just like Shuttle, if this turns out to be hopelessly optimistic, the whole model falls apart and it becomes rather pricey.

277:
I know there are various colors and flavors of design of inflatable heatshields for aerobraking (I haven't checked to see if any have actually been tested, mind you)

It turns out, NASA actually has tested one of these! Check out the HIAD program.

So far, it's failed. The idea seems good, though.

If you want something really fun for aerobraking though, check this out: A Plasma Aerocapture and Entry System for Manned Missions and Planetary Deep Space Orbiters

278:

Re: LV

Small world ... just heard from family that an old friend is there on business (not gaming).

Looked up the convention calendar to see who's there this week: it's the gaming convention with 26,000 attendees. Communique about recent events on their home page below.

http://www.globalgamingexpo.com/

279:

Well the ones I was discussing, were the Carleton (now Cobham I think) A5800, which was basically a MK16 but with a slightly different harness. (the Australian navy thought their balls were bigger so they needed two crotch straps to go around their nuts instead of over)

No that's not really true (sadly), I think it had something to do with a requirement to lift a diver by their harness. Almost everything else was a MK16. I think there was another tiny change but it was getting on for 20 years ago now and I've forgotten...

I also worked on the Drager LAR-V and FGT. The FGT was the non-mag version of their FGG and all the metal had the consistency of stale cheese. I have no idea what the metal actually was. Scary kit... I didn't do a lot of hands on work on the FGT, that was mostly done by a guy who I see in my head when I read about Angleton. He'd been working on them for decades. I did the scut work and he came in like a master artist and did the tricky stuff.

I also was one of the founders of ARGG which was a sort of home builder collective, and came up with the over the shoulder design for counterlungs. In a bit of parallel evolution the inspiration later used the same design, and on the first ones even the same colour! I don't think they were aware of my work though. In fact it appeared that the Inspiration crew were so deeply clueless that they didn't know which was the inhale and which was the exhale side. They simply copied the Drager gear (the name of which escapes me) which was a front mounted LAR-V worn on the back and converted to semi. When you wear a front mount on your back, the hoses are wrong way around.


So I got to play with a lot of different kit, but sadly didn't get to dive the military stuff. For some reason they didn't want me taking them home on the weekends.

280:

You are right. The engines represent the bulk of the dry mass as they are increased in number to increase thrust. At 25 kg each, one cannot scale up the vehicle fast enough to make sense. (The solar array mass to support them is almost inconsequential, especially with ultra-thin film arrays.)

So it looks like the performance limitation is going to be the thrust to weight ratio of the ion engine. Other approaches need to be used to improve that factor by an order of magnitude.

281:

Ion drive power. Now, I know they weigh a lot, but don't know at what point RTG's might produce more power than solar panels. Plus, still good further out.

Fuels. Hypergols. Someone who was very close to me, Dian Hardison, worked at the Cape for 17 years, and one of her main specialities were hypergols. She told me that when she interviewed, they asked her how she felt about them. Then they explained that they're two deadly poisonous and dangerous chemicals that when flung together exploded. She got the job, because she was the only interviewee that *didn't* run out of the room screaming.

A common set is Monomethylhydrazine (MMH) + Nitrogen tetroxide.

Oh, and she led the team that did propellants on Cassini-Huygens and Chandra. In fact, for her work on Chandra, she got one of NASA's highest awards. At that level, you get to pick who gives you the award. http://dhardison.5-cent.us/ And yes, that older black woman handing her the awards *is* Nichelle Nichols.

She died in '12. And yeah, it's hard for me to talk about her, but she should be remembered for the work she did.

282:

As I said to Moz's email, ARRRRGHGHGHGHHGHGH!!! Nobody else has pointed that out to me in years....

Yes, "fad". Maybe I'll get around to fixing it tonight.... Hope the content of the article was of interest.

283:

Ion drive power. Now, I know they weigh a lot, but don't know at what point RTG's might produce more power than solar panels.

That's a 'nope', until you get ridiculously far out from the sun (past Jupiter, maybe past Saturn).

RTGs basically produce decay heat constantly from a medium half-life isotope (typically 1-50 year half-life). You then need to figure out a way to get electricity from this. Peltier effect is good and solid-state; Stirling-cycle engines have also been proposed as a way of turning heat into reciprocating motion to drive a generator, for deep space missions.

The trouble is, you've got to dump your waste heat overboard in deep space. Background is only 2.7 Kelvins, but you can't use conduction or convection because it's a vacuum — you have to rely on radiation, and your RTG is not that hot in absolute terms (unless you want to have to deal with the thermal headaches of a spacecraft with some bits close to absolute zero and other bits glowing red hot). The bigger your radiator panels the more efficiently you can dump heat so the more power you can extract, but they add mass to a spacecraft — probably at a similar rate to the way increasing power from PV cells adds weight (it's proportional to your solar panel area).

284:

Also RTG power output is a few hundred watts at most, an ion drive wants kilowatts.

285:

Yes it was. Thank you. (I test stuff for a living, and one time I was responsible for ensuring that one of my then-employer's publicity flyers didn't go out the door with the word "uranuim" in it... :D )

286:

The article was interesting, but I admit to spending more time thinking about short-lived dads (reminds me of some horrid vagina dentata inspired scifi short story I read as a youth) than the nominal content. It wasn't new news to me rather than not being useful.

287:

Nojay (et al) re: mining saturns rings: gasdive is right when they say that saturn's gravity well is pretty deep. I was hazarding a guess at needing about 10-15km/s delta-v to escape from the rings and return to earth, but this answer suggests you can get away with a bit less: https://space.stackexchange.com/a/5513

In either case, that's a pretty hefty overhead unless you've got nuclear power, and combined with the substantial lead times (6 years+ flight time, one launch window every year or so) it isn't obviously competetive with fuel shipped from earth. That ain't no way to run a space program.

(incidentally, if you haven't heard of "delta-v maps", they're interesting little toys, though they lack quite a lot of information they're ok for ballpark figures. http://www.projectrho.com/public_html/rocket/images/spacemaps/RocketCatUniverse2.png)

288:
The whole economic idea underlying their plans is that the ship is going to really be fully reusable, in the way people envisioned the Shuttle would be early on. That is, basically airliner style: just gas and go, with scheduled maintenance.

Yeah, that seems pretty over optimistic. If that's required I wouldn't be surprised to see the whole thing fizzle out in relatively short order. If it isn't I can see it being collossal money sink.

I'd like to imagine that those billions of dollars might be more usefully invested in one of the alternative propulsion schemes that have been dreamed up in the last 60+ years... one that doesn't require hundreds or thousands of tonnes of fuel per trip, which would provide a slightly better return on investment. I suspect I'm pretty over-optimistic too.

289:

Monomethylhydrazine (MMH) + Nitrogen tetroxide
Runs out of room, screaming .....

290:

I did say right at the beginning that this sort of endeavour would take a lot of time and a lot of money before the first tanker of water-ice arrives in Earth orbit from Saturn, decades and trillions of dollars. The key is to establish a pipeline operation where then second tanker arrives a few months after the first, the third a couple of months after that and so on. It's only then there's a return on investment but it still won't pay for itself for another decade or more, another hundred tankers or so and it will still need new (or emptied) tankers being launched from Earth orbit to feed the up-side of the pipeline.

Anything lifted off Earth has to accelerate at more than a gee to go anywhere, the thrust has to exceed the mass (well, duh!). Because of that it takes a lot of fuel to get up even before you start going round. The rocket structure has to be able to support that mass under multiple gees so it's big and heavy and that takes more fuel to get up and go around. In the end to get a tonne of fuel into Earth orbit takes fifty tonnes or more of fuel burnt but it gets it there in a few minutes because it can't hang around. That's why fuel or anything else in orbit costs $5000 a kilo.

From Saturn's rings a slowboat tanker carrying a thousand tonnes of water-ice worth $5 billion dollars FOB LEO can be a lightweight structure powered by a small low-thrust motor at, say, 0.01 gee. It doesn't need a hundred tonnes of parasitic weight to contain the load and deal with the low acceleration. It's going to take ten years or more to get from there to Earth orbit, possibly involving a pass or two by Venus and/or Mars to lose some delta vee but barring accidents it WILL get there. It might consume a few hundred tonnes of fuel to do so but that's 1:3, a lot better fuel:payload ratio than 50:1.

Asteroidal ice might be better, it's closer and less gravity-bound and there are some promising candidates already identified, also maybe carbon-rich asteroids that could provide fuels such as CH4 if enough water-ice can be obtained locally. There are short-period comets of some interest too but they often lie further out of the plane of Earth's orbit so they'd need a correction burn to get to them and another to return to LEO after harvesting.

The difference is basically in time -- to get fuel into orbit from the Earth surface it takes minutes, from somewhere else in the Solar system it takes decades. The Moon might (might!) provide a middle solution of a few days cycle time, assuming there's enough water-ice there that can be harvested easily.

291:

but it does represent two years of the world supply of Xenon

My understanding is that xenon is expensive and supply is low because nobody ever built a dedicated facility for it. Xenon comes as a byproduct of making liquid oxygen; there was never enough demand for it to extract xenon as a goal in itself.

When demand for ion engines becomes great enough, somebody will build such facility. IIRC, xenon precipitates from air at -40 C and 25 atmospheres of pressure, which means in places like Iceland or Siberia it can be produced with pressure alone.

292:

Ion engines tend to use xenon because it performs a bit better than the cheaper alternative, argon (Xenon produces less Isp oddly but it takes more energy per Newton of thrust than argon due to higher ionisation energy). Since it costs more than $5000 a kilo just to get fuel into orbit the extra cost of xenon is basically a rounding error given the extra performance it provides.

293:

It's not a rounding error if there is literally none to have because you (or your competitors) are consuming it faster than it is produced.

294:

2 SPAM entries on A bright and shiny page

Thanks

295:
I'd like to imagine that those billions of dollars might be more usefully invested in one of the alternative propulsion schemes that have been dreamed up in the last 60+ years.

Allow me to play... well... I guess Devil's Advocate isn't quite right, since I'm actually promoting SpaceX's rather optimistic plan rather than the plucky nuclear underdog. But anyway:

So far as I know, almost every single one of those interesting alternative schemes involves inventing a new, more exotic form of nuclear reactor which combines lighter weight with increased power density. Specifically, the ones which have ever actually had any real engineering done are:

  • NTR (Nerva): Scary compact nuclear reactor. Isp: 850-1000 s.
  • NTR (Nuclear Lightbulb): Terrifying vortex of uranium hexafluoride plasma at 12,000 C contained within a crystal prison by a wall of neon gas. Isp: 1500-3000 s.
  • Orion: Um, actual nuclear bombs. Isp: a lot.

There are a whole bunch of other cool ideas like fission fragment rockets and so on, but except for the totally hypothetical nuclear saltwater rocket which is somehow even scarier than Orion, they're all replacements for ion drives, not launchers. The one exception, I guess, would be external power schemes like laser launch.

Do any of these ideas really seem like they're going to get us into space more readily than some fairly modest improvements in existing rocket engines, lightweight tanks, and reusability?

296:

ATTN CHARLIE: specimen of CUNNUS SPAMULOSUS identified at http://www.antipope.org/mt/mt-cp.cgi?__mode=view&blog_id=1&id=7299 (2 spams in the previous thread).

Thanks

297:

I think it's close to 300 that I can introduce this new topic. I found the following article:

https://www.opendemocracy.net/digitaliberties/chenchen-zhang/curious-rise-of-white-left-as-chinese-internet-insult

Note that I can't vouch for the trustworthiness of the source, but the author does seem to have good credentials.

My comments

1. As it has been argued in the comments, this might have to do much more with rights for Tibetans, Mongols, and Uyghurs?

2. Africans who settled in Guangzhou have encountered a lot of racism, and paranoia about the community is popular within Chinese social media, or so I heard when I was in Japan in the early part of this decade
https://en.wikipedia.org/wiki/Africans_in_Guangzhou

3. I wonder if this is in any way sponsored by the government as a cover to declare anyone who believes in a multicultural existence an "enemy of the state"? Perhaps it's a new excuse to crack down on human rights groups?

298:

Re: '... sponsored by the government as a cover to declare anyone'

Most interesting tidbit:

'The Chinese government has been known to hire a large number of ‘internet commentators’ (known as the 50 cent party) to fabricate social media posts. According to a recent research conducted by scholars at Harvard University, 29% of the ‘accused 50 cent posts’ they investigated fall into the category of ‘taunting of foreign countries.'

Could be they're baiting the hook looking for potential human rights activists.

If all gov'ts decided to go all-out xenophobic, how would they rationalize on-going international trade? Especially China whose economic growth is still largely tied to the West.

OTOH, this could be: the West keeps going on about how enlightened they are about human rights and building a peaceful society. But it's all talk, no action: just take a look at how they treat their own nationals of X race, Y religion, Z gender. (Unfortunately plenty of examples.)

299:

Well currently it's about 1500 dollars a kg, fob in China. That's before you increase demand several fold. So it's not *insignificantly* more expensive, but it's not *hugely* more expensive either. If you start deciding that you want a particular isotope (lighter means higher ISP) then costs go up, a lot. 124Xe is about one molecule in 1000 of Xe. So I guess you'd be looking at somewhere in the order of 1.5 million dollars a kg. But you would get about 5% more performance.

Speed costs, how fast do you want to go?

On the other hand, some plans for saving the planet involve liquifying the whole atmosphere (bit by bit rather than all at once). So there might be more of it available than one might think. Who knows?

300:

The Apollo-Soyuz mission was in 1975. Carter didn't become president until January 1977.

301:
t's going to take ten years or more to get from there to Earth orbit, possibly involving a pass or two by Venus and/or Mars to lose some delta vee but barring accidents it WILL get there. It might consume a few hundred tonnes of fuel to do so but that's 1:3, a lot better fuel:payload ratio than 50:1.

How are you going to power your ion drive? You're going to need a nuclear reactor. There are such things as nuclear reactors in space, but they all have a poor power-to-weight ratio and are not yet suitable for powering engines. Even when you do have one, people are showing a very strong disinclination to put anything nuclear powered in space right now, as you may have noticed.

So you're currently needing unavailable technology (lightweight space-capable nuclear reactor, a large high power-to-weight ratio ion drive) and a minimum of 13 years mission time (hohnmann transfer out and back, 1 year wait for a launch window at saturn, and that requires a certain minimum amount of thrust to do your injection in good time and your ion drive is almost certainly not going to be able to provide that) and you need to be able to rendezvous safely and autonomously with big chunks of ice and bring em back.

If you've already done 5 impossible things by breakfast, why not round it off with breakfast at Milliways?

Forget saturn. It is a silly idea. You'd be better off getting ice from the moon, or maybe one of the martuan satellites if they happen to be sufficiently icy.

302:
So far as I know, almost every single one of those interesting alternative schemes involves inventing a new, more exotic form of nuclear reactor which combines lighter weight with increased power density.

Nuclear rockets are almost as old as spaceflight, and aren't ever going to take off again because everyone is scared of nuclear tehnology. Forget them. I'm also well aware of the issues with lightweight nuclear reactors, let alone the political issues associated with making them and then getting them into space. Given these obvious constraints, you should perhaps concentrate on proposals that don't involve either approach.

The one exception, I guess, would be external power schemes like laser launch.

Oh hey, a system that might give you a good 1000 second Isp with a simpler fuel requirement and single stage to orbit! Yes, that's a pretty important "one exception".

Myrabo's lightcraft is vaporware at this point, and I suspect that making a high-power ground-based laser launch system is probably about as welcome in the current geopolitical climate as a nuclear rocket. On the other hand, you could stick magbeam sattelites in low orbit and use them to boost payloads in a suborbital trajectory into orbit. That might reduce your launch delta-V to more like 4km/s, which is a colossal improvement, don't you think? That's the sort of thing I'm thinking of. Unlike pulsed laser systems, magbeams won't make for good weapons, which is a significant point in their favor.

Do any of these ideas really seem like they're going to get us into space more readily than some fairly modest improvements in existing rocket engines, lightweight tanks, and reusability?

Current rocket technology is great for getting into space, but pretty awful at getting reasonably sized payloads to another planet in a reasonable length of time.

303:

With respect to ridiculous ways to propel spacecraft, the one I like best is the "alphabet(a) drive":

Place a sheet thin sheet of heavy metal laminated with a sheet of a strong alpha or beta particle emitter isotope at the tail end of your spacecraft with the isotope pointing backwards.

Bonus edition: a tiny gap of vacuum between the two sheets and you get electricity as a byproduct.

304:

How are you going to power your ion drive? You're going to need a nuclear reactor.

The water-ice tankers from Saturn are propelled by LOX/LH2 motors using cryogenic gases cracked from water-ice in Saturn orbit using very large solar arrays, compensating for the reduced solar flux Out There. They're part of the trillions of dollars of upfront investment for the project I mentioned.

Ion drive tech is something else and power for big ion drives pushing big spacecraft is a perennial problem involving waste heat as well as compact reactor design, very large solar panels, foccussing lightsails and all. Chemical rockets are easy, lots of compact energy in the fuel and oxidiser and the waste heat of combustion is dumped in the exhaust stream with no high-temperature intermediate stages such as reactor heat exchangers kept on board.

305:

A quick one-source check on the Nets suggests xenon costs about $1200 per kilo. Argon is cheap, say $12 per kilo. SpaceX bills at about $5000 per kilo into orbit (but that includes the mass of the vehicle delivered into orbit, tankerage etc.) so xenon propellant in orbit costs $6200 per kilo where it performs nearly twice as well as argon at $5012 per kilo in a smaller lighter engine with lower energy requirements. Like I said, it's a no-brainer to choose xenon in that case. If argon-based ion thrusters can be improved sufficiently and/or the cost-to-orbit of a kilo of thruster hardware and power supply falls by a factor of ten or so then xenon thrusters may go out of fashion in favour of cheaper argon.

There's about 2 billion tonnes of xenon in the earth's atmosphere, I understand compared to about 60 trillion tonnes of argon. It's rare but not rare enough for its use in ion engines to be a major depletion factor. The big six-tonne Boeing geosync satellites fitted with ion thrusters for station-keeping have about 75-80kg of xenon on board and that is expected to last them for 15 years or so.

306:

Shawyer / Fetta drives anyone?
Table of comparative results
See also

I know almost everyone is so determined that "It can't work" that many are not looking at the admittedly extremely variable actual results, but it is beginning to look as thaough NASA & the PRC are getting SOMETHING form their set-ups.
I happen to be of the very poorly-informed opinion that the drive is akin to a QM "h=Hydraulic Jack" ( I.e. where you can lift a 2-tonne car by hand, because the pressure is equal over the two bearing surfaces, but the lifting surface is large, & the pressing (raisng) surface is small, give a huge mechanical advantage. )
The differential sizes of the "EM drive" work in a similar manner, maybe, perhaps. But, I also suspect it requires really good precision in manufacturing tolerances & preferably a superconducting medium for the casing ....
The former problem would certainly account for the huge differences in results.

As one of the articles says - in effect - bugger the theory, let's have a practical test.

307:

An important point about Musk's roadmap to BFR:

Shuttle failed on the reusability front because of a lack of iterated progress; it was basically a prototype of a reusable spaceplane that got pressed into service. There were a couple of generations (Columbia and Challenger were heavier/less useful than the later-build shuttles Atlantis and Discovery), but the changes were minimal compared to, e.g., the plans for Concorde B (which never got built), never mind the changes between a Boeing 707 and a Boeing 737.

In contrast: Falcon 9 is now on version 1.5. It kinda-sorta looks similar to Falcon 9 1.0, except for the legs, and the stretched tankage, and the uprated motors, and the modified plumbing, and the software ... I think it's more appropriate to say that current, flying Falcon 9s are "nameplate-compatible" with the original Falcon 9 (which was emphatically disposable and had about half the payload). But it's really a case of George Washington's Axe gradually morphing into a chainsaw. Incremental change towards a design goal ultimately resulting in a different vehicle. Whereas the Shuttle was pickled in aspic for the most part — one major engine redesign for the SSME in about forty years, for example.

So I think Musk has a much better chance of getting to full reusability with BFR than NASA ever did with the Shuttle, simply because it's very unlikely that BFR 1.0 will bear more than a superficial resemblance to BFR 1.6b or whatever ends up hitting the design goal.

308:

I largely agree with this assessment. Falcon 9 block 5 is yet to fly, but I think its level of success will be strongly predictive of how SpaceX will do with BFR. If block 5's first stage really is 'kick the tyres and light the fires' the way they seem to be hoping, then...

309:

Going back to the BFR, what can the US military do with it? This is the biggest revolution in power projection since the invention of the aircraft carrier.

310:
The water-ice tankers from Saturn are propelled by LOX/LH2 motors using cryogenic gases cracked from water-ice in Saturn orbit using very large solar arrays, compensating for the reduced solar flux Out There.

So you're still throwing away 90% of your fuel, only now you also need vast self-assembling solar power stations and fully automated fuel refineries so far away that they'd better be self-maintaining because you're not going to get any interactive repair work going on out there.

They're part of the trillions of dollars of upfront investment for the project I mentioned.

Now, I'm no venture capitalist, but the prospect of putting the most expensive, most ambitious engineering project a billion miles out into space and waiting decades for a return does not appeal, especially next to the prospect of investing in an earth-based system to take water out of an only slightly deeper gravity well, with colossally simplified assembly and maintenance requirements, smaller cheaper and simpler power supplies, instant payoff and an upfront cost that is orders of magnitude cheaper.

You didn't respond to my earlier comment about getting ice from somewhere closer, either. Moon, martian satellites, the asteroid belt... all much, much easier to reach than saturn and in much shallower gravity wells and much closer to the sun. I'm just not seeing what upsides your saturn plan actually has.

311:
This is the biggest revolution in power projection since the invention of the aircraft carrier.

Is it, though? Projecting force via space seems to be a good way to make your neighbouring super-ish powers pretty twitchy. See also, arguments against hypersonic travel made on this blog and elsewhere. Doesn't that just leave them putting up more of the sort of things they already use, just slightly bigger and slightly cheaper?

312:

I did say the diehard was really good at what she did. I did *not* say she wasn't crazy....

313:

I'm for NERVA, which, if I have it right, was actually ground-tested in the early seventies.

And you'd want to ship it up, some assembly required, and *never* bring it down again. Spent fuel rods? Um, the Sun's thataway.

314:

Mining" More like capturing Saturn's ice from the rings (um, isn't there ice in Jupiter's rings?)

But that's all silly. Stick a NARVA-style reactor on on, and use the ice itself as fuel. Or maybe just solar panels, and a mag track, and throw some of the ice away at high velocity - mass driver.

Really *gotta* finish my Famous Secret Theory.

315:

Shuttle. Reusable. CRAP!

They had to replace good numbers of the insulating tiles. And - you'll love this - they were *not* identical. They had to be keyed in.


And inspecting the Shuttle on the road to relaunch: the Diehard's take on why we lost Columbia (btw, her's is one of the many signatures on the report on Challenger) was *not* lost tiles, but stress microcorrosion cracking on the hydraulic lines. They break, at max-Q during return, and you've got "a mach 25 set of house keys". And to inspect.. she didn't know who was inspecting them after she was gone, being that she could just get in... and she was 5' on a good day, and 105 pounds, soaking wet.

316:

Re: 'It's rare but not rare enough for its use in ion engines to be a major depletion factor.'

Made me wonder whether anyone has studied what effects these inert gases have on our planet's total ground-to-atmosphere system. For example, whether our planet's atmosphere needs a certain level of inert atoms floating about to moderate the speed and types of biochemical reactions that occur. Have heard that these gases do have important electromagnetic properties - not sure what as the papers I clicked are paywalled and their Abstracts very terse. The few known neurological effects seem to be related to pressure (diving).

317:

Neurological effects... xenon is a general anaesthetic. Not just an asphyxiant that displaces oxygen, but something that actually knocks you out in its own right. How the fuck that can possibly be true, given that it's an inert gas, I cannot understand at all, but it is true enough that the stuff can be used medically.

318:

We are certain there is ice in Saturn's rings. The case for recoverable Lunar ice is somewhat more dubious, same with the Martian moons. I'm all for landers and probes going to those places and looking for ice and it will be great if they find it but I'm sketching out a fuel supply project that actually has a known resource to start with at the end of it. If there is a way to get that Lunar/Martian water-ice to Earth orbit or some convenient waystation instead of bringing it all the way back from Saturn orbit then it cuts the cost significantly (and the cycle time too which also improves the return on investment) but it's still going to cost trillions and take decades and a lot of launches to get enough hardware in place to start the process -- it's not a question of just putting a thousand tonnes of refinery in Earth orbit, it has to get somewhere which will take another five hundred tonnes of fuel minimum, especially if it has to soft-land somewhere.

The main benefit of working in a ring system (Saturn, Jupiter, maybe Asteroid Belt) is that the refinery doesn't have to be lowered down a gravity well onto solid ground in a zero-zero landing, it can just rendezvous with ice in free flight. That's also a disadvantage as it's easier to build and operate stuff if there is a local gravity field to hold things down etc.

My BOTE calculation suggests a thousand-tonne load of water-ice delivered from Saturn ring orbit using a high-efficiency vacuum-optimised LOX/LH2 motor in a slowboat trajectory might use up 10% or so of its payload, much of that matching Earth orbit at the end of its travels. It could take ten years or more with possibly a couple of fly-bys of Venus and Mars to achieve Earth orbit depending on the celestial mechanics involved. It helps that LOX/LH2 in vacuum is about the best we can get out of conventional chemical engines (the Vulcain 2 has an vacuum Isp of 429 compared to the SpaceX Merlin vacuum-optimised 1D's Isp of 348 using LOX and RP-1).

319:
I'm for NERVA, which, if I have it right, was actually ground-tested in the early seventies.

And you'd want to ship it up, some assembly required, and *never* bring it down again. Spent fuel rods? Um, the Sun's thataway.

Its the getting the fuel up there that's the problem. Spaceflight may be getting cheaper, but there are still some reliability issues... Fuel rods though, it might actually be financially viable to do a good bit of reprocessing on them. Shipping up new fuel assemblies is pricey, and there's that fallout hazard that gets everyone so unhappy.

Nuclear rockets are problematic for other reasons though. They really don't like being turned off, cooled down, and fired back up again. That's inconvenient for using them as orbital shuttles, or for return trips to mars, etc.

(also, much as it would be lots of fun to throw things into a star, you need something like 25 km/s delta-v to do that, which is Quite A Lot. still waiting for practical solar sails...)

320:
How the fuck that can possibly be true, given that it's an inert gas, I cannot understand at all, but it is true enough that the stuff can be used medically.

Plenty of of inert gases cause interesting biological effects... nitrogen narcosis, for example. The gases need to be lipid soluble, so they can dissolve into nerve cell membranes, but what happens after that is anybody's guess.

321:

Re:: Xenon anesthesia

Thanks!

https://www.ncbi.nlm.nih.gov/pubmed/21067086

'Xenon exerts its anesthetic properties, in part, through the noncompetitive inhibition of N-methyl-D-aspartate receptors.'

FYI: 'A noncompetitive inhibitor binds to the enzyme away from the active site, altering the shape of the enzyme so that even if the substrate can bind, the active site functions less effectively. Most of the time, the inhibitor is reversible.'

Which immediately elicited an Oh sh*t! because NMDA receptors are a very big deal in neuro, see below:

https://en.wikipedia.org/wiki/NMDA_receptor#Neural_plasticity

322:
it's still going to cost trillions and take decades and a lot of launches to get enough hardware in place to start the process

I'm going to go out on a limb here and suggest that bringing stuff back from the moon is going to cost at least two orders of magnitude less than bringing stuff back from saturn. Remember also that you don't need ice; there are alternative fuels (such as aluminium-oxygen) which can be made from regolith which are enough for getting stuff back to earth. And alternative engines that those trillions of whatevers might be more reasonably invested in for a better return.

It could take ten years or more with possibly a couple of fly-bys of Venus and Mars to achieve Earth orbit depending on the celestial mechanics involved

Launch windows for that sort of trajectory are not everyday occurrences. That might end up being ten years out, plus a ten year wait, then ten years back. Whilst seriously hoping that no-one has found more convenient ice, or a more suitable engine, or perhaps more likely, that your autonomous self-constructing refinery hasn't simply broken beyond repair.

323:
Unlike pulsed laser systems, magbeams won't make for good weapons, which is a significant point in their favor. [....] Current rocket technology is great for getting into space, but pretty awful at getting reasonably sized payloads to another planet in a reasonable length of time.

I actually quite like beamed power and think it's pretty nifty. However, let me now rubbish it, because I was brought up to be a surly contrarian.

First off, magbeam satellites (or any beamed power from space) really aren't going to be a factor any time soon. You need many gigawatts to power such a rapid change in kinetic energy, and satellites are low-energy affairs. We can certainly imagine building huge laser or microwave arrays on the ground, with the associated death ray questions. However, I think this is all kind of missing the forest for the trees.

You mentioned an Isp of 1000 s in the launcher, which makes me want to ask a simple question: why do you care about Isp at all? I mean, seriously: is Isp a goal? I'll argue that it really isn't.

The goal is cost-effective ways to put things in orbit, and to send them around the solar system. Buying propellant has really never been a significant proportion of the cost of space flight: a Falcon 9 supposedly only carries about $250k worth of kerosene/LOX, which works out to on the order of $10/kg to orbit. At that price, space is cheap.

Rather, the vast bulk of the cost has always been in salaries, operations, expendable airframes, ground equipment, and R&D which is never paid for by low volumes. Even the much maligned Shuttle was said to have a marginal launch cost of only $45 million: it was low flight rates and massive fixed costs really that broke the program.

The problem with carrying an enormous amount of propellant around is really the side effect of needing to build a vehicle that has such a large tanks for its mass. But the solution of course has always been staging: an SSTO doesn't work, but a 2 or 3 stage rocket is fine.

If you assume an Isp of 1,000 s, a beamed power SSTO is still going to need a mass fraction of at least 60% to get to orbit. SpaceX is proposing about 80% plus staging: both look fairly poor compared to an airliner at 40%. Complexity seems similar... I'm just not seeing a world-changing improvement here. It seems like an incremental technology, and it doesn't address all the other technical issues.

As for moving around the solar system, chemical rockets work fine. Sure, you need a lot of propellant to do it, but on the plus side you get the Δv all at once. Three months to Mars is really quite excellent.

324:

Hmm... interesting! Thanks for that.

325:

that your autonomous self-constructing refinery hasn't simply broken beyond repair.

Or that it never worked in the first place. Now you're 10 years in with a long train of empty tankers headed out there and no way to fill them up without waiting another 10 to 15 years for the repair tug to show up. Or a replacement refinery/filling station.

Oh, yeah. I'm guessing matching the delta V of the frozen ring rocks is no big deal. So do you meet up with them with a tug which hauls things back to the AMM, (autonomous miracle machine), or have the AMM move about and directly meet up with the frozen rocks?

326:

Even the much maligned Shuttle was said to have a marginal launch cost of only $45 million: it was low flight rates and massive fixed costs really that broke the program.

I think that number was ignoring a lot of costs that would not exist without the shuttle but were not directly involved in the launch.

I read one back of the envelope estimate that the all in cost of recovery of the SRBs but not accounted for was around $5 million in the 80s. Thinks like the recovery tugs and doc equipment to unload the tugs. And a minor thing like how much extra were the coast guard costs to clear the ocean of anywhere they might possibly land.

SpaceX also has these issues. I have to wonder at times just how the accounting for them works? Does the Coast Guard send someone a bill these days?

327:
Going back to the BFR, what can the US military do with it?

If you look at the ground kit requirements both for taking off and for landing, I think a good mental model for this system is more like an infrastructure program such as a subway. What can the US military do with a subway?

They could clearly use it for launching more satellites for less. Other than that, there are all the good old orbital bombardment ideas which might become cheap enough to build, but really why would the US military of all people need such things?

328:
First off, magbeam satellites (or any beamed power from space) really aren't going to be a factor any time soon. You need many gigawatts to power such a rapid change in kinetic energy, and satellites are low-energy affairs

More like tens to hundreds of megawatts for a modestly sized payload (10 tonnes, as per Winglee's paper), and only for the time when the beam is actually operating which ends up only being for a few minutes at a time so if you can build a good power storage system you can make do with much smaller solar arrays. You might need to lift lots of big heavy batteries to orbit, but the payoff comes afterwards when you can use dinky little suborbital lifters that you could practically make in your shed.

Such a system isn't going to beat the BFR for lifting Really Big Things (eg. a magbeam facility) but it'll cost a hell of a lot less for everything else.

You mentioned an Isp of 1000 s in the launcher, which makes me want to ask a simple question: why do you care about Isp at all? I mean, seriously: is Isp a goal? I'll argue that it really isn't.

It isn't the be-all and end-all, but ~1000s occupies a convenient sweetspot for an SSTO which lets you avoid all that tedious and sometimes hazardous mucking about with staging. A laser launch system also allows a single propellant to be used (though I think it still has to be hydrogen for launches from earth, so you can't make a non-explodey rocket) which makes for a simpler rocket motor, simpler interior design and less plumbing. Finally, the most expensive and bits of the launch system are easily recovered and reused, because they won't generally move very far from the building you put them in when they were assembled.

I'll agree that higher Isps aren't particularly useful unless you're flying a very long way.

Anyway, beamed-power SSTOs aren't the only game in town either; there's plenty of scope for other interesting ideas, like star tram and other electromagnetic catapults. Sure, those things will cost tens of billions, but it'll be worth it to see the look on the faces of those people who just sunk trillions into that saturn fuel depot boondoggle...

329:

I'm going to go out on a limb here and suggest that bringing stuff back from the moon is going to cost at least two orders of magnitude less than bringing stuff back from saturn.

Definitely. You do have the problem of landing (expending a lot of fuel in a hurry) and taking off again against a constant gravitational field which means you can't fly a very fuel-efficient slowboat trajectory as you can away from an orbiting refinery. The orbital approach means the tankers can be very lightweight structures, tinfoil and moonbeams, never pulling more that 0.1gee.

Remember also that you don't need ice; there are alternative fuels (such as aluminium-oxygen)

Oh, there's all sorts of Powerpoint presentations about alternative fuels (the fluorine-based tripropellants are a scream, literally). What's flying today is a mixture of solids, LOX/RP, some hypergolic mixes and LOX/LH2. Bring ice back to Earth orbit and we know we can burn it in quite efficient engines once it's converted into LOX and LH2. Lunar regolith is a different matter (so to speak). If we had a few hundred tonnes of the stuff to experiment with in labs down here then maybe... what's that Skippy? We don't have a few hundred tonnes to play with? Bummer...

Launch windows for that sort of trajectory are not everyday occurrences. That might end up being ten years out, plus a ten year wait, then ten years back.

It's more like tanker flight X is launched with an expected arrival time in Earth orbit twelve years in the future. Flight X plus 1 launches two months later on a different flight path with two passes of Venus before its arrival in Earth orbit nine years in the future, two years before Tanker X. If there happens to be a really good trajectory opportunity coming up (eight years, maybe) it might be worth waiting to send several tankers out in one go but they really need to be sent because the empty tankers still have to get sent back to the refinery to get refilled. It's a pipeline after all.

As for reliability we're getting a lot better than we used to be on that front, and space is quite a good preservative (no moisture, wind, corrosive oxygen etc.). The Voyagers are still operating pretty well forty years after launch although some stuff (moving parts mainly) are flaky. Cassini was crashed deliberately into Saturn only after nearly running out of fuel, twenty years after launch and twelve years after decelerating into the Saturn system with one of the longest-ever burns of a working rocket motor (90 minutes). The Hubble telescope is still operating over thirty years after the Shuttle successfully deployed it. Any sort of unmanned refinery/tanker system would have redundancy and a low-cycle of operation with only a dozen or so tankers each year visiting. Sure it could still break but them's the breaks. A Lunar-based refining plant would be suffering from the 4-week cycle of being on a solid rotating body exposed to harsh sunlight and freezing dark cold, dust, micrometeorite strikes etc.

330:

OTOH having no atmosphere on the Moon does mean you're relieved of the problem of having to launch stuff vertically and make your first priority struggling out of the atmosphere before you can do anything useful, so you can instead launch stuff tangentially off a surface track, using ground-based power and efficient coupling. (And reverse the process for landing, although getting everything lined up right might be a bit tricky.) Your vehicle does have to be able to support its own weight at 0.16g, but you can still accelerate it gently if you have a long enough track.

331:

It's also just occurred to me that the four-week day/night cycle could be used to make a solar heat engine, operating on a near-ideal Carnot cycle and with a very low rejection temperature, to power the lunar plant. You'd compensate for each stroke taking 2 weeks by making it very large and having a whole ring of them right round the Moon.

332:
You do have the problem of landing (expending a lot of fuel in a hurry) and taking off again against a constant gravitational field which means you can't fly a very fuel-efficient slowboat trajectory as you can away from an orbiting refinery.

You do however have the advantage of being able to make a catapult launch system, something waaay easier in the shallow lunar gravity well. Construction and maintenance could be done by almost-real-time remote, as it isn't a billion miles away. There's not necessarily a need to land every tanker on the moon, just an occasional shipment of lifting frames with minimal guidance and a motor which could be packed down well enough to survive a bumpy landing.

Oh, there's all sorts of Powerpoint presentations about alternative fuels

People don't make and use rockets of this sort commercially, because you need the higher oopmh of the commonly used propellants to get out of the thick atmosphere and gravity well of earth, and they don't do it in the military because they have quite a different set of storage and longevity requirements. The chemistry works, and fixed tester motors have been operated, there's just no other particular need to use them in anger right now.

what's that Skippy? We don't have a few hundred tonnes to play with? Bummer...

We've bought back ~300kg of moon rock, and found another ~200kg in lunar-origin meteorites on earth. The composition of the moon isn't a complete mystery, skippy.

As for reliability we're getting a lot better than we used to be on that front,

We aren't anywhere near the level of reliability required to run a hands-off self-assembling, self-repairing industrial facility with the biggest solar panels ever made (which will have to be self deploying) for decades a billion miles away from earth, whilst independently intercepting irregularly shaped lumps of rock and disintegrating them and safely dealing with waste products.

The tankers aren't the problem here. They're replaceable, and assuming your trajectories plan out there'll be another one along in a month. A refinery failure will set you back decades.

A Lunar-based refining plant would be suffering from the 4-week cycle of being on a solid rotating body exposed to harsh sunlight and freezing dark cold, dust, micrometeorite strikes etc.

We do have experience of running stuff on the moon for extended periods of time, mostly bad experiences, but these problems aren't intractable. Also, something which is busily engaged in mining and processing rocks need not be exposed to the sun for very long, if that was deemed undesirable. And I haven't even got into the realms of the silly-but-not-as-silly-as-other-things-mentioned-on-this-thread of beamed power from orbiting satellites to run the heaters!

There are places at the north pole that enjoy continuous sunlight. There are also polar craters that get no sun at all, making them likely places to find ice. I'm not sure how close the two are, but it is worth bearing in mind.

(fun fact: lunar terminator moves at about 16km/s, I think. I wonder if you could hop or drive your refinery fast enough to enjoy perpetual sunshine...)

333:

(incidentally, I should probably point out that I think the idea of mining the moon with plausible near future technology is a very silly and pointless one, just less silly and pointless than trying to do the same thing around saturn)

334:

We've bought back ~300kg of moon rock, and found another ~200kg in lunar-origin meteorites on earth. The composition of the moon isn't a complete mystery, skippy.

And that's enough to determine the best place to put down a refinery to process regolith, some random samples and a few interesting-looking rocks chosen specially (the Apollo 17 mission had a trained geologist on board) and Lunar meteorites from a billion years ago? Right.

It's all moot. There's nowhere in the Solar System we really want to go anyway so sourcing fuel above LEO isn't justified even over a period of centuries. Robots can do the exploration in radiation belts and long-duration flights and Kessler-syndrome ring systems without having to lug meatbags along and the robots tend to get to LEO already tanked up for the trip ahead.

335:

Even the much maligned Shuttle was said to have a marginal launch cost of only $45 million: it was low flight rates and massive fixed costs really that broke the program.

Yeah, back in, I guess, the early '90s I was in a discussion about NASA's claim that Shuttles only cost $50M-ish per launch. The discussants ran out several estimates including RDT&E, infrastructure structure and maintenance, cost-of-money etc. and easily came up with per-flight numbers ranging from NASA's $50M to $2000M ($2G). Each was right taken on its own terms and the right one to present to a decision-maker asking about the cost depended greatly on when and why the question was being asked.

336:

Even the much maligned Shuttle was said to have a marginal launch cost of only $45 million: it was low flight rates and massive fixed costs really that broke the program.

Some of the retired people involved mentioned that detail that the low flight rates were due to many of the parts had to be taken out and inspected/refurbished after every flight. And some of those parts were only accessible if you removed the main engines. Add in facilities and manpower costs for that.

Again, as CS said, the shuttle was really a prototype that Congress declared would be a production device.

337:

Neurological effects...

Speaking of neurological effects, could there have been something on the paper the prankster/protester handed Theresa May that caused her coughing fit?

338:

Here's an article from Bloomberg on renewable energy

https://www.bloomberg.com/gadfly/articles/2017-10-04/renewable-energy-iea-projections-coming-at-you-fast

Here are some of my favorite statistics

"The message there is that coal's share of the global power mix slipped slightly from about 41 percent in 2001 to 39 percent last year. Renewables, meanwhile, climbed from about a fifth to one-quarter"

"We see renewables growing by about 1,000 gigawatts by 2022, which equals about half of the current global capacity in coal power, which took 80 years to build."

339:

Re: Coughing fit

No magic or woo-woo needed. Talc can cause a coughing fit.

Or surprise someone enough so that they gasp (take a huge involuntary deep breath) in a dry and dusty environment. Gasping sucks in particulates deep into the lungs so that more particulates touch or even get embedded in the lung tissue which causes more coughing. Hurts like hell and can be serious. (Know someone who broke some ribs from a coughing fit.)

340:

Pigeon: you will note, also, that lithium ions also have CNS modulation effects and lithium is used as a treatment for manic depression. Nobody is quite sure how that works, either, but it's speculated that it may competitively block a trans-membrane ion channel in some neurons.

As for Xenon and anaesthesia, we don't really know how general anaesthesia works in the first place, or why a sudden blow to the head causes (reversible) loss of consciousness! Again, we have speculation — mostly around the fact that our brains are a whacky emulsion of fatty acids in dirty aqueous solution, and nerves touch each other via processes (synapses) that may connect via microtubules which are fragile and prone to disruption, but it's one of those unsettling questions that are to biology much as Olber's Paradox was to physics and astronomy in the 19th century ... a ticking bomb, waiting to explode under the entire field.

341:

Ah, thanks: things have moved on since I had to study this shit.

(I will note that a noble gas binding to an enzyme away from its active site is itself a bit of a WTF?!? moment ...)

342:

Also a known side-effect of ACE inhibitors (antihypertensives) — note that May has Type II diabetes, which is one part of the package known as metabolic syndrome which also includes hypertension, so there's a good chance she has high blood pressure as well.

Also a symptom of a chest infection, and she's just spent most of a week at a party conference, where she will be mixing with thousands of party activists, delegates, and lobbyists, all breathing a fug of bacteria and viruses in the hotel and conference centre. (Convention-going SF fans know it well as "con crud".)

343:

Ref para 1 - Even without knowing the lady's actual medication regime, I'd agree that a "pril cough" is not impossible on this basis.

Which means that she suffered an perfectly normal side effect from her medication, albeit in a very public place. Move along folks; nothing to see here!

344:

Nojay wrote:
It's all moot. There's nowhere in the Solar System we really want to go anyway so sourcing fuel above LEO

Let's just say you, and a *lot* of the rest of us have a serious disagreement here. Hell, some of us really *did* think we'd be able to buy a ticket, at least to orbit (on the PanAm Shuttle) by 2001. I'd plunk down $20k that I'm saving to pay off my ex's share of the house to get to orbit, and to the Moon? Who do I have to screw? Do I need to rob Ft. Knox?

And I know we won’t stop.
We’ve planned too many wonders for one little star.
Though often the present may seem too complacent to take us that far.

But I’ll tell the story and I’ll draw the picture
And I’ll sing the anthem that banishes doubt,
And host the convention that summons the family
That carries the fire that never burns out
There are so many chances to give up the journey,
Especially when it’s so easy to stay,
But I am willing to sacrifice
Something I don’t have for something I won’t have
And not only me,
But we are willing to sacrifice
Something we don’t have for something we won’t have
So somebody will,
So somebody will someday.

--- from Somebody Will, Sassafrass

345:

OT: not a good day or two for conservatives. Good time for pranksters. On this side of the Pond, if you haven't seen it yet, google equifax hearing monopoly, and look at the pic.

If you've never played the board game Monopoly, google that, and you'll see the "rich" person that's part of the trademark....

346:

Ha, for me it's exactly the opposite - it is only by taking an attitude like Nojay's that I can view such discussions with equanimity. All the casual talk of single devices that use energy at a rate comparable to the entire capacity of the UK's electricity grid fair gives me the willies, and the idea of firing them off often enough to make it worthwhile to provide and maintain an interplanetary propellant supply network to send them on the next stage of their journey is quite appalling. I don't have a problem with the occasional mission for purposes of scientific exploration (knowledge acquisition), since it is only occasional, and since it can be done far better by robots than by meatbags which is a much less extravagant proposition. But in this "bulk" context, I need the comfort of being able to argue that there's nothing outside Earth's gravity well that we can't get vastly more easily at the bottom of it and therefore it'll never happen, in order to stick such discussions firmly in the realm of science fiction which is the only place I'm comfortable with them.

347:
There's nowhere in the Solar System we really want to go anyway

You are making teh assumption that humans must be colonizing the solar system for there to be any need for infrastructure and transport. There can be an entirely robitic ecosystem that is producing power and materials for Earth-based civilization. We need to remove as much of teh polluting economy from Earth to make it more livable and hopefully, sustainable. Humans in space will be for tourism, a relatively few specialists who need to be onsite, and colonists who want to be away from Earth. They will probably live in O'Neills, which will be built by robots and be ready for occupancy.

348:

Some links accumulated while waiting for thread to reach 300. The only things I care about in space are more up-and/or-down-looking scientific instrumentation, maybe more deep space probes, and work towards a possible eventual extraplanetary solar shield, which might need to involve self-replicating machinery. (e.g. at L1)

Equihax: fact enabled wild speculation
Some interesting details and speculations, but this quip is new to me:
The important things are always simple. The simple things are always hard. The easy way is always mined. – Murphy’s Laws of Enterprise Information Security.

One step closer to personalized microclimates (potential eventual big reductions in HVAC energy usage)
Electrically heated textiles now possible
Paper is paywalled (Transforming Commercial Textiles and Threads into Sewable and Weavable Electric Heaters)

For those of us with flabby brains, exercise can help!!! :-)
Structural plasticity of the social brain: Differential change after socio-affective and cognitive mental training (04 Oct 2017, full, pdf available)
We demonstrated a training-specific change in cortical morphology after three different mental training modules focusing on improving mindfulness-based attention (Presence), socio-affective skills (Affect), and socio-cognitive capacities (Perspective). Notably, module-specific thickness increases correlated with individual improvements in attention, compassion, and ToM in respective behavioral markers after training and, in part, overlapped with functional networks obtained from tasks targeting module-specific functions at baseline before training.
No excuses. :-)
(Note that the above applies to adult brains (ages 20-55 studied).)

Terrified Sigh. Via Carbon feedback from forest soils will accelerate global warming, 26-year study projects,
Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world (6 Oct 2017, abstract-only without access, can be found in usual place)
We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms.

349:

Surprisingly she actually has type 1 diabetes.

350:

Some interesting details and speculations, but this quip is new to me:
The important things are always simple. The simple things are always hard. The easy way is always mined. – Murphy’s Laws of Enterprise Information Security.

Those are the old Murphy's Laws of Combat. They're one of the first things I learned when I got internet access.

Some of my favorites ...

Friendly fire isn't.
Incoming fire has the right of way.
If it's stupid but it works, it's not stupid.
If the sergeant can see you, so can the enemy.
If you can't remember, then the claymore IS pointed at you.
Once you pull the pin, Mr. Hand Grenade is no longer your friend.
Never share a foxhole with anyone braver than yourself.
Never draw fire, it irritates everyone around you.
A clean, dry set of BDUs is a magnet for rain and dirt.
Never stand when you can sit, never sit when you can lie down, never stay awake when you can sleep.

351:

Re: Forest soil and CO2

Was looking up what organisms eat up CO2 when this SciAm article showed up: a modified microbe that converts CO2 into methane and other products. Very versatile and modifiable organism (R. eutropha) already being studied for outer space applications: habitat atmosphere scrubber and food production. Mentions alcohol being removed during production, so maybe even the makings of a space still. Not a magic bullet, but could help.

Imagining a promo for a 'suburban house of the future blending the best of old and new into the latest carbon-sensitive lifestyle: passive solar water heating, grey water toilets, rain barrels and drip irrigation, PV panels, clothes line. Everything prefabbed to your specs including a convertible patio with solar oven/BBQ spit, and a stylish CO2 still. This week's special is a selection of the latest designer essences for your ethanol of choice whether vodka, gin, rye, scotch, brandy or liqueur.'

Free booze? - Could work.

https://www.scientificamerican.com/article/scientists-engineer-bacteria-to-make-fuel-from-co2/

352:

Mumble. Mumble. Pence bloviated yesterday about a moon mission. *

I still don't think it's going to come within a million miles of actually happening. Trump is apparently bent on antagonizing Iran, and Mueller is still collecting evidence. Congress ain't gonna give Pence or Trump even a single fuckin' nickle to fund another moon mission. And did anyone notice Trump's comment about the "calm before the storm."

Despite the bloviation, not gonna happen.

* I think he actually meant that the "moon would go missing" because the Republicans want to steal it too.

353:

Yes, I know, so did Dan Quayle (VP under Bush I). On the other hand, sounds to me like he's ramping up his campaign of "don't impeach me too"/Can I invoke the 25th Amendment yet?/Pence in 2020"

Innit interesting how the one undisclosed campaign can do all that at once?

354:

And since we're well past 300, let me add that I'm *really* tired, and going to a *lot* tireder before I get home to bed sometime after 01:30 tomorros - was up late last night, backing a large, decorated cake for the [HINT, HINT, PLEASE SUPPORT, TRUMP"LL BE GONE LONG BEFORE THEN] DC in '21 bid party tonight at CapClave.....

355:

Actually, what just struck me was this: the Orange Doody hasn't spent almost any time on space, yet the announcement of the joint project for the DSG this week.... I wonder if it's *Pence* who's pushing NASA....

356:

Re: "All the casual talk of single devices that use energy at a rate comparable to the entire capacity of the UK's electricity grid fair gives me the willies, and the idea of firing them off often enough to make it worthwhile to provide and maintain an interplanetary propellant supply network to send them on the next stage of their journey is quite appalling"

At least in theory launch plus re-entry could be made energy neutral, think airplane landing on an aircraft carrier and the catapult storing the energy needed to decelerate the plane...

357:

Sadly, not really on any body with an atmosphere. Orbital speed is very, very fast, and decelerating in space is just as energy-sapping as accelerating in the first place. The closest we can get to decelerating for free is hitting the atmosphere with a heat-shield, but this converts almost all of the kinetic energy to heat way to fast to be captured. (It's hard enough surviving it, and all energy conversions* have efficiency limitations. *Okay, maybe not gravitykinetic in deep space...)

Your simile to an aircraft catapult has the same problem, namely friction losses unless you can capture external energy (like a glider climbing thermals.)

Otoh, it CAN work* in a vacuum (think on the Moon), as the friction losses once it leaves the catapult are negligible. *Without more energy put in at another point in the orbital, your payload /will/ be revisiting the catapult.

358:

I'm pretty sure the Tangerine Shitgibbon has zero interest in anything he can't sell, steal, or fuck. Space is a big nope on all three of those scores.

Pence's religiosity is at least in principle compatible with Federovism (albeit in some kind of bastardized protestant-compatible version, assuming Pence isn't a pre-millennarian whackjob).

359:

I had the good fortune to visit a NASA facility earlier this year, and although no one said it outright, it seemed pretty clear at that time that Pence was the final authority in the administration about NASA stuff (this was around the time that he was touching things he shouldn't have...).

Not sure about why the change in focus back to the Moon. It could be a purely "Obama bad" reactionary change (IIRC Obama changed NASAs immediate manned flight goals from back to the moon under Bush Jr., to a direct Mars mission); it could be the new NASA Administrator nominee Jim Bridenstine who is on the record as being for going back to the Moon; it coule be Pence; or it could be something as simple as a Moon mission meaning more pork for certain congressional districts compared to a Mars mission. But I'd be shocked if it was Trump.

360:

Pence's religiosity is at least in principle compatible with Federovism

Manifest Destiny in Spaaaaace!, along with Evangelizing the Aliens? (you know, if they existed)

361:

There's a few ways around that.

There are also serious engineering difficulties.

So one is the rotating tether. It's long string in low earth orbit. Spinning end over end so that the end closest to the ground is going opposite the direction of orbit. Needs stronger string than we have now to be practical, and there are some stability issues to overcome with spinning thousands of tonnes of string in a steep gravity field.

Another is the Moon catapult you mentioned. Stick it in orbit. Want to deorbit a spacecraft? Fire it backwards. Now it's sitting at zero velocity with respect to the Earth. It falls back to Earth. No heat shielding needed. In reverse, shoot the spacecraft back up with zero orbital velocity, the catapult sweeps it up and brings it back to orbital speed with electromagnetic regeneration. Zero net energy use (apart from inefficiencies of course). Make up the lost energy with solar panels, make up any lost orbital speed with reactionless drive pushing against the Earth's magnetic field.

It's all doable, but needs a stonking big cheap chemical lifter to get the whole thing started. Enter the BFR (or more probably its distant descendent.

362:

Zero net energy use (apart from inefficiencies of course).

Inefficiencies and differences in payload mass spinning down versus spinning up.

So we're basically talking about some high tech analogy of a tow rope on a string. And since we're also talking Skyhooks, I'm enjoying this living in the 70s.

Assuming that the whole idea is to lift net payloads into orbit, even with perfectly efficient conservation the system would lose energy by the amount of mass going up minus the mass coming back down. Therefore to work, we'd also need to stash a quantity of additional ballast mass in orbit at the orbital speed we want to reach. We then use some of this mass to top up the energy to harvest from the drop. Of course this reservoir is usable separately.

It's hard to say whether making this from something lifted from Earth, from the moon or by capturing an asteroid, it still also needs it's own BFG or whole family thereof, and massive sunk energy cost.

363:

Re: Saudi Arabia & United Arab Emirates

No one's mentioned these two even though both have space programs and a few recent headlines that show SA and Russia cozying up. Even Bloomberg has written about the Middle East joining the space race. SA mentioned a few years back that it intends to land the Kuran on Mars by 2030 making space the new religious battleground.

364:

It's probably not possible to build one for the Earth. However if it is, it would be built on the Moon first, where it would be easier, so it wouldn't be hard to drive the system by moving mass from the Moon to the Earth.

http://www.tethers.com/papers/CislunarAIAAPaper.pdf

365:

Assuming that the whole idea is to lift net payloads into orbit, even with perfectly efficient conservation the system would lose energy by the amount of mass going up minus the mass coming back down. Therefore to work, we'd also need to stash a quantity of additional ballast mass in orbit at the orbital speed we want to reach.

Asteroid mining.

366:

Assuming the accounting for space based solar begins to look better as construction materials are sourced off-planet.

367:

I can't see asteroid mining being any less impossible than going to Mars, TBH. It's worse than going to Mars, time- and radiation-wise. The payback time is enormous, and the project risk of the whole thing going bust or being cancelled before completion has to be big.

The physical risks are probably worse, given that you want to throw unpowered, unmanned rocks accurately into Earth orbit, and hope they don't disintegrate on the way. Get that one wrong, and hope you were underneath it.

368:

So yeah, bread and circuses.

OTOH it would be a convenient way to get rid of inconvenient humans. "Oh he took a job on the No-Return Project. Unexpected, really, his only expertise is in economics. No, we haven't heard from his since. Why do you ask?"

369:

"assuming Pence isn't a pre-millennarian whackjob"

I couldn't find evidence to support such an assumption.

370:

This reminds me of a blog post by my second favorite author (you being the first :hat_off):, John Michael Greer, which two months ago talked in detail about "The Worlds That Never Were" in the classic science fiction :
http://www.ecosophia.net/the-worlds-that-never-were/

In the off chance that you aren't busy up to your eyeballs, and you might be interested, he's launching a new writing contest (see details at the end of the blog post) :

[...] we’re looking for short stories (2500-7500 words), novelettes (7500-12,500 words) and maybe a novella (12,500 words on up) set in the Old Solar System. What kind of stories? You name it. Two-(or more-)fisted tales of adventure like C.L. Moore, solar system noir like Leigh Brackett, interplanetary travel with a religious dimension like C.S. Lewis, Old Solar System horror like Clark Ashton Smith – you name it, so long as it takes place in the imaginary solar system of the classic science fiction era. You can—indeed, you should—put your own twist on ancient and desolate Mars, lush Venus, or whatever other world or worlds you choose for a setting—and yes, Earth is also an option!—but it should fit more or less cleanly into the grand collective work of art that was the Old Solar System. [...]

He has also talked a bit about the space program and especially about the human exploration of space in the 20 September post "The Terror of Deep Time" (at the root of the blog, I won't directly link it here so as to not risk triggering the spam filter).

And you might also be interested by his discussion of Lovecraftian prose (since you share his appreciation for that author's work) in "Our Shoggoths, Ourselves" of 4 October (not linking directly for the same reason) - he's planning to write yet another book in that universe and he's describing in that blog post how as an author he got the idea for that book.

371:
So one is the rotating tether.

Rotovators are pretty fun to think about. One of the bits that may not be obvious is that you really don't need them to be zero energy / momentum: because they're in orbit before and after boosting a payload, you can re-boost the tether platform using high-Isp ion drives or similar efficient propulsion. In this way they resemble a way to use ion drives for Earth launch.

Boeing actually did some engineering work on these: Hypersonic Airplane Space Tether
Orbital Launch System

The basic summary was that this could maybe be designed using existing string materials... assuming of course that the the vehicle shuttling payloads from the ground is a hypersonic scramjet capable of flying in excess of Mach 10 and docking with the string 80 km up.

372:

"assuming of course that the the vehicle shuttling payloads from the ground is a hypersonic scramjet capable of flying in excess of Mach 10 and docking with the string 80 km up."

When you're in the business of building hammers...

Boeing builds jets. So their design looks like a jet, with strings attached. I could easily imagine a Falcon 9 with a thing that looks a bit like an inflight refuelling probe on the tip flying into a basket at the end of a string that looks a bit like the basket at the end of a refuelling hose. SpaceX has already demonstrated rockets landing on a target a couple of metres in diameter. From what I can figure the expendable F9 MICO happens at up to about Mach 8 and 80 km altitude. Sticking a slightly lighter stack on top of an F9 1st stage should mean you can do the surface to tether manoeuvre with an existing F9 1st stage with enough fuel for a landing. So that means that the whole of the slightly lighter 'second stage' could be payload. So you'd probably bump the reusable payload up from about 10 tonnes to LEO to about 100 tonnes to the tether. (currently the 1st stage has about 120 tonnes sitting on top) Not far off the BFR's estimated payload of 150 tonnes.

Of course you could do something similar with the BFR, should you be able to get enough string into orbit. So it should be able to take somewhere north of 1000 tonnes surface to tether.

373:

Been in Pasis for 2.5 days
"Calm before storm" - don't like that, what is shitgibbon on about?
Korea?

374:

You think we know the mind of DT?

ROTFL

Except it's too scary.

375:

It may not mean anything. It could mean anything. Maybe the chemicals in Trump's brain decided that "the calm before the storm" was the right thing to tweet. Or maybe he has an actual plan. When your actual best-case scenario is "Maybe Trump and his friends will blow into town, steal everything that isn't nailed down, and head for Leningrad just before the subpoenas are served" and your worst case scenario is "total thermonuclear war..."

Maybe the best thing we can do is keep calm and... you know.

376:

"Calm before storm"
Briefly, and without nearly enough thought to comment coherently but will try (mundane life intruded):
Been assuming North Korea[4], and to be clear, there is a clear and I presume deliberate threat of nuclear attack buried as a possibility in the ambiguity of that "calm before the storm" comment. I'm more than a bit freaked out. [1][2][3]
Haven't seen any other obvious tells in the mainstream press; will do a harder/wider look today. It has the superficial appearance of a Madman Theory play, but if so, (a) do they understand KJu well enough to do it properly (of course not!), (b) as the article says, it didn't work for Nixon and Nixon was a lot better at these games (IMO), (c) what exactly are they negotiating, (d) DT may have mentally operationalized the Madman aspect a little too well (plus he's burning out mentally), and may sometimes or always actually believe it (that can be a part of a madman theory play), (e) (this is a personal judgment call based on viewings of old and new video) DT's negotation skills have deteriorated quite noticeably since their peak, (f) he has no Kissinger-type to help compensate (AFAIK; could be wrong about this). (And etc, barely touching on some aspects. Interpreting negotiations as an outsider is hard.)

I would forgive DT for a lot if he pulled off the Best "Deal of the Century" Ever!!! with the North Koreans. It would be something to legitimately brag about for the ages.

[1] There is also the obvious possibility that North Korean nuclear forces are structured to fail deadly, the mere possibility of which should cause planners to be seriously scared.
Given Kim’s overarching concerns about regime change attempts, one has to assume that the system is designed to fail-deadly — making sure his units will launch nuclear weapons if the regime is believed to have been decapitated is the only logical deterrent posture.
[2] DPRK alliance with China
[3] Worth it for the posthumous and correct mockery of some of Herman Kahn's work - Stale Thinking on Tac Nukes Reheated
...epitomized by Herman Kahn’s tome, On Escalation: Metaphors and Scenarios. Published in 1965, Kahn suggested a notional escalation ladder of no fewer than forty-four rungs. In Kahn’s fertile mind, signaling escalation and escalation control was akin to buying a new Studebaker from the dealer and haggling over the price. I’ll see your five kilotons and raise you ten. Your move.
And that's with good predictive models of the opponents on both sides.
[4] other possibilities seem less likely. Decertifying the Iran nuclear deal as not in the US national interest has been floated as another interpretation. (I hope somebody in the administration has actually read the JCPOA (links to pdfs towards the end); I have, including the annexes, and it is a solid, detailed agreement; also it is working. Not entirely facetious; many statements from opponents including this administration suggest a lack of knowledge of the contents of the agreement and of the context.)

377:

Think [1]is pretty unlikely at this point in time (give it a couple more years) so the real concern today is their conventional forces shelling Seoul.

378:

Suggestion in the "Indie" that DT is simply interested ONLY in revenge on Obama
- Linkie here

379:

I'd have to agree. Unless you count empty rockets burning up on reentry in the middle of the Pacific as a 'nuclear attack'. Despite the western press's manic banging of the war drum, NK hasn't demonstrated anything beyond making a small number of unguided medium range artificial meteors. Building something that is powerful enough to carry an actual warhead, goes where you want and then reenters the payload gently enough that it will still detonate is orders of magnitude harder. They may get there eventually but not yet. Of course you wouldn't get that from the press who are hitting the panic button with a 5kg sledge.

This whole thing could be ended in a few hours with an abject and public apology and a sue for peace from the USA. Something that played well in the NK press and let the Dear Leader look good.

The problem is that the whole shebang is being run for domestic consumption both in the US and NK by their respective leaders, both of whom feel a bit precarious.

380:

JCPOA .... suggest a lack of knowledge of the contents of the agreement and of the context.)

To his base this agreement was we paid them a bribe of 100s of millions of $ to stop doing nuclear. The don't get (and will refuse to ever get) that this deal was about giving them back the money we had held in escrow (ransom) for the last 40 years if they would shut down their nuclear.

So his base will mainly never agree to anything but give us (USA) back the money and stop doing nuclear. Which is not gonna happen. Nope. Nope. Nope.

Just like his comments on trade agreements, which in the end are 90% nonsense, they appeal to his base like red meat which is all he cares about.

381:

They may get there eventually but not yet.

The real question is how much help are they getting from Pakistan or the PLA under the table. Many of the more coherent analysis of what they have done so far points to them getting a LOT of help.

382:

This post relates to a conversation in a previous thread.

Charlie mentioned that Brexit and Trump are driven by the relative decline in relative wealth.

I've gone back and looked at the numbers for the US.

In 2000, the US had a GDP of $10.28 trillion. The global GDP was $33.54 trillion
In 2016, the US had a GDP of $18.57 trillion. The global GDP was $75.24 trillion

In short, the US went from being 30 percent of the global GDP to being 24.6 percent. This doesn't look like that large of a decline. It's certainly smaller than the media has been indicating in their focus on the rise of China.

Haven't looked at the other countries yet.

383:

Calm before storm

Pick one or more from below. (And maybe non of them)

Fire RT
State subsidy payments for health care will stop unless Congress fixes this in 30 days. Or does repeal and replace.[1]
Announce combat patrols around NK.
Break the deal with Iran.
Fire Mueller
Fire Sessions.
....

[1] Welcome to the arcane of running the US government. I think I've got this right (without doing some digging) that when O and the D's passed the ACA they never got around to passing the spending authorization. The ACA contained the process for how the subsidies would work but they never passed the separate bill as required to actually pay them. So far everyone (mostly) has gone along with this setup but DT does has the authority to not write the checks. Not paying these will create enormous upheaval in the US economy but then again DT claims to be elected to do just that.

384:

And if you want to know how far DT is pushing even his supposed allies, Mitch McConnell is standing firm in keeping the 60 vote requirement for much of Senate business. He has the ability to wipe this out and go with a simple majority for everything.

But he is smart enough to know that the R's will not be the majority forever. Maybe not after Jan 2019 if DT keeps acting as foolishly as he is now. And the odds for that are getting better every day.

385:

I suspect the thing you're missing here is that global GDP more than doubled, and US GDP less than doubled. Meanwhile, the GDP of those Americans who aren't very rich stagnated, IIUC.

386:

What happened in the last 30 years was that if you thought you had a secure union[1] (or not) job in simple skills required manufacturing you go hosed if you thought your high school or less education would do you for life.

I lived in Pittsburgh from 80 to 87 and one reason I left was I was tired of dealing with people without a high school diploma being mad that no one would pay them $20/hr[2] for a job. After all that's what they had at the mill or local factory before it closed up.

And yes some of those jobs went overseas. But more went to automation and the rest of the world not buying as much Made in the USA as in the past.

[1] I see the need for unions to keep employers from being total asses in come situations. But I also see many unions in the US that turned into extortion organizations.

[2] Worth between $45 and $63 per hour in today's $$$ per the CPI calculator I found. Which leads to an annual wage of between $90K and $125K per year. With no real education or hard skills.

387:

Re NK nukes

Dumb question time:

- How many of these tests before there's serious nuclear materials related damage to the area and inhabitants? (If there is an LD50 for nuke testing, that's when this idiocy must stop and NK desist.)

- Apart from any nuclear materials discharge, are there any other toxic or noxious materials associated with such a test that could hurt the flora/fauna around the test site and/or the areas that this device flies over? (At what rate do these accumulate and their LD50 levels?)

388:

Think [1]is pretty unlikely at this point in time (give it a couple more years) so the real concern today is their conventional forces shelling Seoul.
Oh, wasn't clear. Although a US person, I'm not really thinking about a NK nuclear attack on the US, which is agreed quite unlikely at this time.

I think about this probabilistically; very very roughly (the numbers are sketches):
More likely is a NK nuclear attack on South Korea (including US military forces there) and (perhaps) one or more major Japanese cities. Plus the chance of escalation if China gets involved.

These would have an uncomfortably high probability of killing several 10s of millions of civilians, including retaliation against NK.
Not a guarantee, but since US military planners do not (or should not) have confidence in their estimates of the strength (yes, that includes existence) of NK nuclear forces and the probability of successfull NK attack/counterattack, they need to estimate; e.g. 20% probability of 10 million civilian nuclear deaths is roughly 2 million (average), worst case is escalation and involvement by other nuclear powers (i.e. the tail is long and very horrible.)
Then there's the massed conventional artillery. I'm sure there are exotic plans for rapidly destroying these artillery forces, but they're probably not worth spit (NK military is thinking hard about this), and South Korean industry and cities would get severely damaged/destroyed. (World economic collapse likely (has anybody modeled this?), if one only cares about money.)

Here's another piece worth a look if for nothing else but the links:
The Rorschach Test of New Nuclear Powers: Analogies for North Korean Command and Control (Austin Long, RAND)

389:

All (well most) of those things are possible happenings, but for the calm before the storm comment,
the context was a dinner with military commanders, hence the concern.
Panetta: Trump's 'calm before the storm' comment a 'play for attention' (link for counterpoint)
Thursday evening at a photo op for a dinner with military commanders and their spouses, Trump had a cryptic message for reporters, which sent them immediately scrambling for answers.

"You guys know what this represents? Maybe it's the calm before the storm," Trump said.

re [1], you're probably talking about Cost sharing reductions, which (non-payment of, including threatened non-payment) are one of the ways that Republicans (and notably DT) are trying to destroy Obamacare without getting too much blood on their shirts. They'll get plenty of blood on their shirts anyway, but the media may give them a pass if they e.g. say it's just fine wine. The thousands of people that they kill, slowly, might not be so accepting. (and -- land of guns)


390:

I still miss the union job I had had a lifetime ago, though it didn't pay as much as those UAW & steelworker jobs. The kind of pathetic thing is so many business folk want customers with lots of cash, and they also all want cheap labor, including skilled labor, and one of those things were the first ones do great and diminishing returns for all the rest. Possibly they'll work this out, but expect some overrun because breaking from a dead end business scheme involves social costs until it becomes painfully obvious to everyone. And applying lots of stress to a society where gun ownership is so popular? The mind boggles.

391:

Sorry, Pence won't evangelize the aliens. According to Ken Ham, all the xeno bastards (if they existed, which they don't) are automatically damned to hell, because while Adam's sin corrupted the whole universe, Jesus only saved us. Manifest Destiny on the other hand... there could be some bizarre theological justification for treating space as the new Canaan.

392:

As I said I can defend or attack unions depending on where they are in their life and industry.

There were a lot of folks in the areas I was in who had wives working to pay the bills as they waited for the "plant" to reopen. Of course the machinery in the plant was loaded onto trucks or sold as scrap and the plants razed. But no matter if a union job opened up they'd have first crack at it. Incredible denial.

Ground zero for me was the couple who lived in the other half of the duplex with me. He didn't finish high school, wasn't all that smart, (not sure if willingly or not), and refused to work for less than $10 to $15 per hour. "He deserved better". His wife got a job to pay the bills while he played video games waiting for the union to call. She threw him out after a year or so. I would not be surprised to learn he was involved in crime not too long after that. He didn't have enough time in service to have a cushion to fall back on.

PS: We lived over the hill from Braddock, PA. Watch the documentary if you can find it:
http://www.imdb.com/title/tt2914052/
The top IMDB comment has a lot of truth in it.

Went back to the area 2 summers ago for a couple of days. Braddock is still dying. But other areas of Pittsburgh are starting to thrive again.

From where I sit it's mainly are you willing to adapt or are you going to demand the world stay static? And I have great empathy for the situation but turning the clock back to 1955 is not going to happen.

393:

IIRC he can't "break the deal with Persia (Iran) without Congess' at-least-partial approval, which I doubt he will get?
He can fire Session, but not Meuller ( or is that the wrong way around? )
Also isn't there a New York State investigation he can't stop, because it isn't "Federal" ?

394:

Which leads to a question:
What nuclear-materlails "leak" would compel the PRC to act?
They don't want any radioactivity drifitng around on theor patch, either (!)
Or, worst-cae, not a nucleat=r attack, but a deliberate air-burst of a DPRK nuke, out in the Pacific?
What to the PRC do then?
( Assuming DT is held in restraint by nice men in white coats at this point :0> )

395:

Depends how bad the north korean testing team are at their jobs. Underground testing has very limited impact, as long as you do it deep enough and in proper geology.

But the north korean nuke program may very well not have the man-power or the expertise to do this right. Or even if they do, may not be allowed enough time. - if testing is happening on the schedule of the palace, whether the miners are done digging deep enough or not, well..

Also, there are signs they may be conducting all the tests under the same mountain which is.. Uhm. Not Correct Practice.

396:

I don't make predictions about the future very often, preferring to make my predictions about the past or present.

397:

The US fired off over a hundred nuclear weapons aboveground in a small area of the Nevada desert over a period of less than twenty years (1945 to 1962). They didn't evacuate anyone downwind of the test sites. The effects on short-term and long-term health of those exposed to the fallout? So negligible they don't even rise out of the statistical noise.

398:

He can fire Session, but not Meuller

He can fire most anyone at the upper levels. I.E. not a civil servant. Or order them fired. And if he tells the DOJ #2 to fire Meuller and they don't do it he can fire them and tell the next one up to do it. (Sessions is out of the loop on this one. I think. It gets weird since Sessions recused himself on this topic but there is a process.)

Any of which would create a firestorm with both D's and R's.

See "Saturday Night Massacre" for the last time such went on.

399:

IIRC he can't "break the deal with Persia (Iran) without Congess' at-least-partial approval, which I doubt he will get?

There's break the deal and break the deal. The President has a lot of power to do "things". So while the "deal" is still in place he can do things against the spirit or letter if he claims Iran is not following their end of the deal. Then you get into proving him wrong. Who does that? Yes groups can sue but there's a problem of standing. And as much as it would tee off more than a few in Congress they do have their hands full right now with multiple deadlines on various "must pass" issues by dates certain than are coming up soon. Especially the Senate.

400:

That was then ...
It was fairly obvious, at the time, that Nixon's time in office was limited after that ... that he would probably jump into a life-raft, rather than be pushed into court ( & prison )
This is now ...
If DT pushes Meuller out &/or Sessions, what then?
DT's still-loud "base" who still believe in this dangerous clown will, unlike then rally around him ...
A recipe for err .. "internal conflict" - since who actually represents the legal guvmint of the USA at that point?

Incidentally, I don't like the idea of the medical financing just being left to wither on the vine, because DT & the ultras will find SOME way of blaming everyone but themselevs for this ...

401:

Depends how bad the north korean testing team are at their jobs. Underground testing has very limited impact, as long as you do it deep enough and in proper geology.

Sometimes things don't go as planned...

https://www.ctbto.org/specials/testing-times/18-december-1970-the-baneberry-incident/

402:

Incidentally, I don't like the idea of the medical financing just being left to wither on the vine

You think we do?

Most of the population wants the current setup to continue until something better comes along. The big money behind the hard core R's are the problem. The will primary a lot of R's if they do anything official to support Ocare.
https://en.wikipedia.org/wiki/Primary_challenge

So we muddle along till DT blows it up. Or not.

Of course if a lot of R's get primaried we could wind up with what in reality is 2 R parties. Which would get strange in our setup.

And much of what might happen also hangs on the Wisconsin case before the Supremes.

403:

A recipe for err .. "internal conflict" - since who actually represents the legal guvmint of the USA at that point?

Unless removed from office it's DT. Period. Our system is a bit different from yours in that aspect.

The R's on Congress, especially the Senate have said they are going to dig into the same stuff as Mueller and want his probe to continue. If Mueller is fired there WILL be a dust up. But it's the house who has to impeach. Or his cabinet shove him out the door. Either of those can get drawn out. But the cabinet route is quicker.

A question I have is if DT starts yelling "You're fired" at his cabinet can they act to remove him before the paper work is signed? I suspect not. So any action by the cabinet would have to happen quickly and in secret. Like in hours. Which would be hard.

404:

Re: Nuclear testing - Oops!

The lifetime risk of developing leukemia is 1.5% for the total of all leukemia subtypes and the incidence in the article is 2.3% which is statistically not different from expectation.

The article didn't say which leukemia these workers came down with or whether both came down with the same subtype. Each subtype has a different lifetime incidence and subtype info is necessary to determine treatment. Lastly, at least 20 subtypes for just one of the four major groups of leukemias (AML) were known when the suit was filed.

IMO, omission of subtype info in a supposed legit news article is suspect/really sloppy.

https://www.lls.org/leukemia/acute-myeloid-leukemia/diagnosis/aml-subtypes

405:

And much of what might happen also hangs on the Wisconsin case before the Supremes.
Sorry, internal USism there, you lost me - please explain?

406:

Also, it's bad when the "MSM" publish stuff like this:
Tillerson will continue his discreet direct talks with Pyongyang, having set up the channel through diligent diplomacy in an attempt to defuse a spiralling confrontation in which Trump has repeatedly threatened to destroy North Korea. In carrying on with the talks the US Secretary of State is ignoring Trump, who has publicly dismissed them as a waste of time.

Just the day before, General James Mattis told Congress that the nuclear deal with Iran was working and should not be scrapped. He stressed that this was also the view of the other international signatories to the agreement with Tehran. The US Defence Secretary was openly contradicting Trump, who has repeatedly vowed to tear up the deal. This follows Tillerson forcing the President in July to grudgingly certify that Iran was complying with the agreement.

At the same time reports have surfaced that Mattis, Trump’s National Security Advisor, Lieutenant General HR McMaster and his Chief of Staff General John Kelly have renewed their pact to ensure that not all three will ever be abroad at the same time. They will ensure that at least one will remain in the country to monitor orders coming from the White House.

This is quite a scene even by the "standards" of the Trump so-called guvmint. It is as if some of the most senior men have decided that it is their (patriotic?) duty to protect the country from DT's worst mistakes. He is facing steady and determined opposition on key issues of foreign policy in the National Security Council with senior members making no secret of their disagreements with him.

You WHAT?
And it's still not possible to get even a significant number to move to impeach?

408:

Ah, we have something called "The Boundary Commission" & it is SUPPOSED TO BE IMPARTIAL.
But, I hae me doots of late ...
They appear to have been proposing new boundaries that cut out marginals, in favour of safe seats for both the main parties.
UM.

409:

You think we know the mind of DT?

I don't think Trump knows either. It's not really a laughing matter, but you got the scary part right.

410:

It has the superficial appearance of a Madman Theory play

I don't think Trump is "playing" at being a madman.

411:

Talking of DT...
The Daily Telegraph is not what you'd call a left-wing paper ... Yet it just published this paywalled article suggesting that DT is totally untrustworthy & so, by extension, is the US ...
Most interestingly, it's by little billy Hague.

412:

I will, willingly, allow Pence to evangelize at me for half an hour straight, no, an hour... as long as he's doing it while *I* am standing on the Moon.

413:

Capture a near-Earth-crossing asteroid, like the one the other week, or Toutatis.

414:

I dunno 'bout them. I *might* have been interested, but starting to read the page, and seeing *all* old SF, the pulps, referred to as almost exclusively the venue of "sweaty-handed teenage boys" for the skimpily-clad women on the cover is more than slightly a disservice to sf, not to mention a complete lack of understanding of the background of the times. By that, I suggest you consider our grandparents, who went from almost nothing electric, and horses, trains, ships and walking, to, landing on the Moon. And the same massive change in people's personal lives - like washing machines.

No, at first glance, I do not like the attitude.

415:

Unfortunately, *no* one knows, and I have doubts that the Thing knows, beyond it being a quick line.

There's a lefty newsblog I read, and they have a very low opinion of Chris Cillizza of CNN. However, he had a column on Friday that was *dead* on: he wound up asking the obvious question: does this man actually understand the difference between a reality tv show and the real world?

Everyone, I think, knows the answer.

Note, btw, there was a column in The Hill today, urging Congress to take control of his war-making powers. In the US, ONLY Congress can declare war. The President's got to come to them to ask. He can do some things, but there are for a limited length of time, after which they *must* come to Congress. And so, Congress can say "no first strike", and if he tries to order one, the entire DOD will call that what it is, an illegal order, and refuse.

416:

Let me start by saying that I do *not* believe Kim is stupid, esp. given some of the extreme things he's done to his own officers, etc.

Given that, the missiles could be one means of delivery... but I'd be surprised if he hasn't thought outside the box... or, rather, inside the shipping container on the container ship in, say, LA, Oakland, or NYC harbor.

417:

Pardon me, but

As far as I'm concerned, GDP means *shit*. I put it on par with "average income". That is, as a most wonderful example an old friend came up with decades ago, you, me, and Bill Gates are in a room, and based on our average incomes, gee, it's great being a billionaire.

*Median* income, on the other hand, varies from "stagnated since the '70s to dropped.

"Recovery" my ass.

418:

About unions....

One HUUUUGGGEEEE problem, esp. in the US, was the fifties and McCarthy and ANTI-COMMONISM (yes, I did spell it that way). It chased all the leftists in power out of the unions. Hell, my own father kept a *really* low profile, and he and the two political comrades I knew as a kid all used their, what is it, nom de politic, rather than real names in the fifties, into the very early sixties. Who came in in many places, like the Teamsters, was the mob, who saw and ran it like a protection racket. Them, and the "co-managerialship" types.

They lost almost all of their goals *other* than wages, and then benefits. All the social goals, and family.... Nope. And they utterly failed to see where things were headed, and lost any understanding of what a union *was*.

Hell, early oughts, my son tried to get into the IBEW, passed the exam, but "failed the interview". And the head of international recruiting told me (email) that "even his own son had failed that, but for my son to try again."

This is as union membership was dropping like a rock, when they should have been dragging people off the street to join. Instead, they thought it was a freakin' medieval guild!

*snarl.

One last note, David - have you ever worked in a factory? And I've read about the steel mills... working there *deserved* those wages. File under the heading of "combat pay", with all the danger. Same as miners.

A

419:

Yes. A *LT* of us were jumping up and down a few weeks ago, when Mueller admitted he was working, not only with the IRS's Criminal Investigation division (and they don't *need* subpoenas to look at OS's tax returns), but also with the NY AG, and neither the President not *anyone* federal can do a damn thing about *state* criminal charges...and we're betting all the tax fraud and money laundering charges are going to be there.

Hell, until Delirium Tremens' lawyer made a $25k "campaign contribution" to the NYC DA, the staff under him was getting ready to file criminal charges against Jared and Ivanka for fraud.

420:

It's already here. -The Reptilian primary for Senate in Alabama, Strange vs. Moore (isn't that a comic book title?), with Trump desultorily supporting the establishment Strange, while the Alabama Inquisitor, Moore, won.

Meanwhile, a poll, today, announces that job approval for DT, nationwide, has dropped to new lows. And, it's only in 12 states that he still has a majority of support (and *that* of course, depends on who was polled....)

421:

A case before the Supreme Court on whether extreme partisan gerrymandering is legal. A similar case was there, um, maybe 10 or more years ago, and the result then was "we can't decided, come back when you have data and methods to decide if that's what's really happening."

Well, they do. I think it was this year that we started reading about "slamming and cramming", where, with the aid of big data, you draw the districts such that the few ones leaning Democratic will get a ridiculous majority, while the larger number of districts will get Rethuglican majorities. One example is in NC, where there's a drawn Democratic district that runs, literally, 80 or 90 miles long, not 5 mi wide at most, and includes three, liberal-leaning cities. Who, of course, are outnumbered by all the districts around them.

422:

Speaking of shooting yourself in the head before your enemies can, Trump dumped this into the pool:

Doesn't he feel a responsibility to honor agreements from previous administrations?

President Trump has a quick response: "No."

Seems to be a legit quote:

https://www.alternet.org/election-2016/8-deranged-moments-trumps-latest-interview-confirm-hes-monster-we-thought-he-was

http://isupporttrump.com/index.php/2017/10/10/inside-trumps-head-an-exclusive-interview-with-the-president-and-the-single-theory-that-explains-everything/

423:

Ah, we have something called "The Boundary Commission" & it is SUPPOSED TO BE IMPARTIAL.

Yeah. Right.

Where do we get these robot people and ensure that only these robot people get on these commissions? Short term they seem to do better. I'm waiting for the next cycle after the 2020 census after all the politicians' data analysts have had 10 years to think about how to game the system.

424:

Sucks to have a 19th century democratic system. I feel for ya.

I did a quick count recently -- it turns out that 52% of the US Senate is elected by 18% of the American population in the 26 least populous states. Rocks and trees do get to vote in the US, a holdover from the days when only propertied landowners (white males of course) got to vote, and it can't be fixed because of the deadweight of the Constitution wrapped around your collective necks. I'd suggest tearing it up and writing a new one more suited to at least the 20th century but it won't happen. Sorry.

425:

One last note, David - have you ever worked in a factory? And I've read about the steel mills... working there *deserved* those wages. File under the heading of "combat pay", with all the danger. Same as miners.

Nothing like a steel mill. I did work as a teen one step removed from the farm. Driving small tractors and whatnot. A 2 pound hammer in the tool box was one of the most used tools. Ever load a water filled rear tractor tire into a pickup truck by yourself in the middle of a field while keeping the salted water from draining out of the hold you just punched into it? Not fun.

But yes I have no problem with people in coal mines and steel plants getting paid real money for their work. But most of the people I was meeting had jobs that were no where near that kind of job. They had the kinds of jobs I had as a teen like wire brush grinding off the casting ridges on metal objects. (Which surely is an automated thing 4+ decades later.) And other than what is needed for steel and similar production deep mining of coal is a stupid idea these days.

I can argue the need for unions and laws to prevent company town setups. I just don't know how to keep them from turning into extortion rackets after a few decades.

426:

One example is in NC, where there's a drawn Democratic district that runs, literally, 80 or 90 miles long, not 5 mi wide at most, and includes three, liberal-leaning cities. Who, of course, are outnumbered by all the districts around them.

The problem with using NC as an example is the D's did the same crap when they last drew the lines. The biggest difference with the lines from the 2010 census is better analytics made it possible to tilt the deck further than before.

Look at this:
https://en.wikipedia.org/wiki/North_Carolina%27s_congressional_districts

Scroll down. If you know the way our cities sit on these maps they in no way make sense except to keep the people drawing them in power. One district the D's put together one cycle back had two population clumps connected by miles of a median strip down a 70mph highway.

427:

I just don't know how to keep them from turning into extortion rackets after a few decades.

The corporations or the unions?

Either way, the solution is regulation and shared responsibility. It's kind of like the US three pillars of government theory, the workplace is a shared/contested space between three parties - the workers, the management and the government. Take away any one of those and the system does not work at all. But if they work together all get something out of the deal.

The trick is to stop two of them colluding to defeat the other. Right now management and government have screwed the workers in many places, and management have largely progressed to screwing the government. The solution is democracy, at least in my opinion.

428:

The corporations or the unions?

Yes.

429:

I don't know, but if you happen to find out, do let us know, because we could do with some too. Our Boundary Commission is supposed to be impartial, but all that really means is it can't be too blatant about exhibiting bias; as long as it gerrymanders only a little bit, too few people make too little fuss to affect matters.

Nojay disparages your undemocratic democracy but ours isn't really any better. Most people are effectively disenfranchised because most constituencies are "safe seats", consistently returning a large majority for one particular party time after time regardless of changing conditions. A lot of people who live in safe seats don't bother to vote because they know it won't make any difference anyway. Elections are decided by the lamentably small proportion of constituencies where the voters are fairly evenly split.

What prevents this being changed is nothing to do with any form of constitution, but simply that it effectively prevents anyone other than the two main parties ever getting more than a handful of seats. We did have a referendum a few years ago about changing to a somewhat more sensible system, but it was a dismal failure, the reason for this being that the sensible choice is bleedin' obvious to anyone with half a brain - but the Sensible Party made the fatal error of assuming that a majority of voters actually had more than half a brain, and therefore would vote in a sensible manner. But when the Silly Party began screaming nonsensical FUD at 130dB and people actually believed it, the Sensible Party were too taken aback at the sudden demonstration of a response both staggeringly dimwitted and unexpectedly widespread to be able to generate any effective counter. Unfortunately, the lesson was not learned.

Much of the root of the problem is that once they've been voted in, the buggers want to stay there, and accord their own good a higher priority than the good of the country as a whole. So here is my prescription for promoting churn:

1) Once the political system switches into election mode (6 weeks before the actual election), all prospective candidates must report daily for a shot of heroin. Missing even one day results in instant disqualification, unless they can prove they only missed it because they were still too off their tits from the day before.

2) When the system switches back into normal mode, the elected MPs are exempted from the laws against possession of heroin, but they are also no longer given a daily shot; instead, they have to find it for themselves. This is not easy, because Everyone Knows that MPs have cops following them about so anyone who deals to them is likely to get busted. But it is "arranged" that "dealers" (hem hem) do appear often enough to make sure they never run out for too long at a time.

3) If they are not voted in again at the next election, not only do they retain their exemption from being done for possession, but they can get as many free shots as they like, not just daily but whenever they want it.

430:

Nojay disparages your undemocratic democracy but ours isn't really any better. Most people are effectively disenfranchised because most constituencies are "safe seats", consistently returning a large majority for one particular party time after time regardless of changing conditions.

That's because populations don't change much in any geographical area between elections and folks generally vote for the same party every time hence "safe seats". Boundary changes can affect this as population changes trigger movements in lines on a map but not often -- my own constituency's boundary has shifted a couple of times since I've lived here but it's remained a safe LibDem seat although it narrowly went to the SNP after the LibDems sold out and became Tory-lites under Cameron and then it returned to being Lib-Dem by 6% most recently with the SNP second. The other main parties have no chance getting elected in this area, but their voters aren't "disenfranchised", they still get to vote.

Sometimes there's a "throw the rascals out!" election but even then the total vote swings aren't that great -- the 1997 GE whitewash for Labour represented only an 11% increase in their vote over 1992 and the Tories still got nearly 10 million votes. Those are once-in-a-generation elections though (the one before that was 1979).

431:

I'm sorry, but it would seem that you've only read the first paragraph, and have missed the point...

As a parallel, notice how more recently comic books and superheroes went from an "asocial nerd" status to a "popular blockbuster movie" status.

Don't you think that it's likely that the people that choose to do their careers in the space program did so because they spent their teenage years imagining the fantastic worlds of the solar system they've read about in the *Weird Tales* or *Amazing Stories*?

And that reviving this genre would indirectly revive our memory of our grandparents and honor their legacy?

432:

With 15 launches so far this year, Falcon 9 has had 43 launches total, 41 successful.

Here are the comparisons

Delta IV: 35
Pegasus XL: 43
Atlas V: 73
Atlas II: 63
Ariane V: 93
Delta II: 153
Ariane IV: 116

I realize that I'm not taking the timeline into account: most of those rockets have existed for much longer than Falcon 9. For instance, I realize that the Delta II was the workhorse for decades.

433:

Don't you think that it's likely that the people that choose to do their careers in the space program did so because they spent their teenage years imagining the fantastic worlds of the solar system they've read about in the *Weird Tales* or *Amazing Stories*?

In the 60s for many of them it was the offer of 50% or more money being offered by NASA compared to the steel plant or electric motor factory.

434:

I have an ancient (>20 years old) memory of reading about one of the issues with what is not ULA rockets is they were derived from ballistic missiles.

They were not optimized for low cost to orbit but to get away from the launch site and air just above it as fast as possible. So they had a lot of intricate machining to make their exterior walls strong and light by machining out the walls to leave behind trusses for strength to deal with the rapid launch stresses. In many ways cost was no object unless totally off the wall obscene. And maybe not even then.

SpaceX and it kin are designed from scratch for cost to orbit. And back. So what if they take 3 times as long to get to 10,000 feet. There's no need to worry about a nuclear weapon going off nearby.

435:

Nuts

what is NOW ULA rockets

436:

So what if they take 3 times as long to get to 10,000 feet.

Rocket engineers don't think that's a good idea. Spending more time to get to altitude and orbit means burning more fuel to fight the 9.86 m/s/s pulling the rocket back down to Earth for most of the trajectory. High acceleration from a light rocket saves fuel and oxidiser which can be traded off for a greater payload with the caveat that the light structure has to be able to cope with the high acceleration.

437:

Spending more time to get to altitude and orbit means burning more fuel

Yes, but as some people have finally noticed, fuel is dirt cheap compared to the price of a potentially-reusable rocket. IIRC the figure for a SpaceX Falcon 9 launch is that about $250,000 goes on fuel; the rest of the double-digit millions goes on rockets and ground support infrastructure.

Doubling or tripling your spend on fuel is money well spent—in fact, a no-brainer—if it buys you the ability to retrieve and reuse your first stage. (And do I need to remind you that SpaceX's launch/retrieval on Tuesday was the second flight of the first stage on that mission?)

438:

Yes, but as some people have finally noticed, fuel is dirt cheap compared to the price of a potentially-reusable rocket.

And even if not reusable. ULA just blew it by not spending a couple of decades working on a new cheaper model that ignore the requirement of a system designed to be launched before a nuclear warhead went off nearby. Now they are stuck way behind the curve.

439:

Fuel costs $5000 a kilo to orbit. It costs $2500 per kilo to half-way to orbit etc. etc. Fuel is mass on the pad that isn't payload into orbit but most of it has to be accelerated to a significant fraction of orbital speed the longer the rocket takes to get up before going round the more fuel needs to be carried and that takes extra tankerage structure which is mass on the pad that isn't payload into orbit. It's not the price at the pumps, it's the transport costs that kill.

440:

"make their exterior walls strong and light by machining out the walls to leave behind trusses for strength"

I saw an interview with Musk many years ago. He basically said the same thing. Existing rocket manufacture takes huge amounts of the most expensive alloy, manufactured and tested to the most exacting specifications, and then puts 99% of the material in the bin.

He was saying that by changing to additive rather than subtractive manufacture he should be able to save 99% of the cost of manufacture, but that he was targeting 90%.

I don't know how close he's come to that, but when he makes anything, the first thing he does is work out the cost of all the materials in the finished product, Y kg of Carbon Fibre at X dollars per kg... etc. That becomes his floor cost of manufacture, then he works out what the absolute least it cost to get all those materials into the right shape and stuck together. Like "there's 500 000 dollars worth of materials in a rocket, but they cost 80 million dollars to build... If anyone else figured out how to make it for 79 million, they'd be "Yay, I've saved a million dollars!" he's more "Well, I'm still wasting 78 and a half million dollars"

441:

Read Gasdive's comment. You're not comparing to anything.

So what if you use twice the fuel. So the fuel costs go from $250K to $500K. If the cost of the booster and engine come down by a million or 5 it's a total win if at the end of the day you're putting a similar mass/weight into orbit.

Again, my point was that for ICBM launches a very major goal is for a 10 minute or less window from command to launch to being miles from the site. That is what drives much of the design of the main booster of an ICBM.

For a commercial launch vehicle the main objective is cost to orbit. Rarely, if ever, does it matter how quickly you clear the pad or how many orbits (within reason) to get to the desired point. So with a totally different set of design goals you come out with a different booster design where those points and others are a derivative of the main objective. Fuel used is one of these items because currently the available fuel supply is somewhat infinite and low cost.

442:

The other goal of ICBM design is a fuel that's stable sitting in the tanks of the missile for years on end, that lights up reliably when you light the blue touch paper and stand well clear. Super cryogenic oxygen isn't one of those fuels.

443:

Interestingly the webcomic Freefall has just started a sub plot involving Chlorine Trifluoride.

http://freefall.purrsia.com/ff3100/fc03030.htm

444:

goal of ICBM design is a fuel that's stable

Yep. There are just dozens of conflicting goals here. One group wants a way to deliver a big bang to somewhere else on the planet on little notice but with a "be prepared to go" for years. The other wants to put mass into orbit (typically) around the earth with long lead times and dates of varrying flexibility. While the devices that meet those goals may intersect at times depending on various constraints, there's no rule in physics that says what is best for one is best for the other.

Way too many variables in that equation when solving for "best".

445:

When I say "expensive" I mean in terms of the extra fuel it costs to get the rocket to 10,000 feet (or 3km in real units). At the moment a modern launcher runs about 1.6 to 1 or better in terms of launchpad thrust to launchpad weight at takeoff. A slower rocket will have to carry lots more fuel to get to 10,000 feet because it's always, always fighting 9.86m/s/s while it's getting there and the longer it takes the more fuel it has to have on the pad which makes it heavier which...

As an extreme case imagine a rocket that took ten minutes to get to 10,000 feet. How much fuel would it have to carry? The fat pig of the Space Race, the Saturn V took 45 seconds of burning 10 tonnes of fuel and oxidiser a second to get to 3km altitude. The Shuttle, less than 30 seconds. A Falcon 9 (depending on payload) will be in the same ballpark.

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This page contains a single entry by Charlie Stross published on September 27, 2017 2:02 PM.

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