Eric S

Comment Threads

• zarzuelazen commented on An age-old question
  Other folks have tried developing methane/LOX engines but they've not been particularly successful hence the current fleet of commercial and government launchers based around RP-1/LOX, LH/LOX and solid motors. No, fully working methane/LOX engines for space flight haven't been developed before - until SpaceX started to develop the Raptor engine, which is a methane/LOX engine. Methane/LOX offers some advantages in terms of Isp over existing mixes but methane engines tend to coke up, break turbine blades and the like. Methane also has downsides in handling, storage and tankerage and it's less dense than RP-1 meaning bulkier and heavier vehicle structures...
• Nojay commented on An age-old question
  The Shuttle had a flexible cargo bay capable of carrying an additional 20-tonne payload, a manipulator arm, airlocks and suit support for multiple EVAs, up to 18 tonnes of fuel and oxidiser for significant cross-range capability in-orbit and enough life-support to keep a crew of seven in orbit for a couple of weeks or a smaller crew for up to a month (never actually done in practice). It also had a toilet and a shower. Dragon X and Orion have plastic bags, diapers and wet wipes, just like the good old (very old now) Mercury/Gemini/Apollo days. They don't have the...
• Vanzetti commented on An age-old question
  The shuttle was a giant White Elephant with a horribly convoluted design. There was nothing it did that couldn't be done much cheaper....
• David L commented on An age-old question
  Yes. It was Congress telling NASA and the US military how to build a single vehicle for wildly divergent uses and the only way anything was going to get approved was to lie about the costs and benefits. Think of Congress telling the US navy that to save money in the future they must combine ballistic missile subs with aircraft carriers and have a single vessel for both missions. I'm still skeptical that the F-35 will actually be cheaper in total costs than separate overall designs for the Air Force, Marines, and Navy. Been tried and failed multiple times over...
• Bellinghman commented on An age-old question
  combine ballistic missile subs with aircraft carriers Sort of like an update of the Japanese I-400 class subs? (Okay, okay, they had torpedoes rather than ICBMs which weren't around in the early 1940s. And their aircraft complement was somewhat small by surface carrier standards. And anyway carrier groups are pretty obvious even if you can't see the carrier in the middle. And your general point is totally valid, it's just that sometimes it seems there's no idea so crazy someone hasn't tried it.)...