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RCgothic

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Everything posted by RCgothic

  1. Very little unless it launches with the payload or can rendezvous with it very shortly thereafter.
  2. I also note that first it was an update 'in a month', then it was 'six weeks', and now it's 'couple months'.
  3. I'm still running the numbers, but I reckon Michoud and the VAB should be able to construct a 125m x 10m diameter rocket powered by 10-12 F1Bs with a 36m x 12m fairing and 800t to LEO in two stages. More with strap on boosters which can be up to 4x 6m diameter. Don't bother man-rating. Just a big dumb booster.
  4. Might be worth establishing a list of things we know we can't throw out. E.g: Vehicle Assembly Building. 125m max height (doors minus mobile platform). Max width 22m. Michoud Assembly Facility. Max core 10m dia.
  5. There are two ways to make a warhead that fits on a missile. One is to miniaturize the warhead. The other is to build a bigger missile. I imagine building a bigger missile is the easier of the two tasks.
  6. Which is then basically ITS.
  7. Falcon 9 is now flying heavier payloads reusable than it initially did expendable. Maybe it might save a little material cost to build a shorter tank for lighter payloads, but you almost certainly wouldn't save more than half the price of a complete booster, as it appears is possible with reusability. Most of the cost is in the engines and if you cut down on mass too much you get over-engined. Redesigning that octaweb is non-trivial. Also, there are additional tooling and inventory management concerns that would eat into your savings. Finally, Falcon 9 went reuseable because Elon Musk wants to go to mars and things like supersonic retropropulsion and reusability are seen as necessary technologies. I'm convinced he'd go for this direction anyway even if it weren't totally financially optimal.
  8. Building a surface colony on Mars is also probably easier than building a floating colony on Venus.
  9. Stage 2 is weird. It provides most of the DV for falcon 9 in order to keep the first stage slow for recovery. But the Space x website advertises the same burn time for F9 and FH second stages, implying no more propellant for S2 on FH. Combined with doubling the payload, that has got to do awful things to S2's DV. Either I'm missing something or the core stage 1 is going to have to separate crazy-fast compared to falcon 9. How then do they plan to do core recovery?
  10. Alas poor Jeb. First casualty of this hardcore campaign. Veteran pioneer of the kerbal space program and in particular the first spacewalk and Gemini Rendevous missions. Killed in a tragic launchpad accident when the launch clamps released prematurely. Unphased he initiated the abort procedure but a second oversight meant that at sea level the munar module did not have enough TWR to pull itself clear of the ensuing fireball. He will be missed. As soon as the space program can find two more credits to rub together Valentina will lead on in his stead.
  11. They probably won't announce that, it being a military payload. Having a winged payload without fins may be doable these days. Heck of a dynamic stability problem though.
  12. I notice that 'fully reuseable' craft doesn't reuse the trunk!
  13. I don't think sci-fi shuttles generally are SSTOs in the conventional sense. When you have enough power to maintain 1g indefinitely you don't have to maintain orbital velocities. Re-entries also don't have to be heat shielded because you don't come in that hot. This also explains why sci-fi ships tend to fall out of orbit when they're damaged/lose power. It's because they were actively maintaining their altitude rather than falling around the planet and missing.
  14. First stage primary mission success!
  15. Go for launch at 27m past the hour! Engines are in chilldown!
  16. As a European I really don't get why Americans do that. :-P Looking forward to the launch!
  17. Yup, fizzle at best (worst?). If a core is not detonated precisely right, the heat of assymmetric fission will scatter the core, leaving the vast majority unfissioned and all that potential energy unreleased. And that's if any fission at all is achieved. Maybe you get none at all and the implosion charges just scatter uranium all over the place. The trick of keeping a mass sub-critical and then making it go prompt super-critical on demand is exceptionally difficult.
  18. At those speeds the difference between hitting a solid and a gas is negligible. Might help if there's time enough for the generated gas to diffuse out of the path, but see again the ridiculously fast speeds involved.
  19. I estimate ~300m/s extra required to get to 1000km and then to a lunar intercept vs starting from 100km and going straight to TMI. Perhaps it's not much. For the moon. It is an extra ~500m/s required for every craft trying to get to the space station from earth though, particularly over the multiple supply runs required.
  20. That was apparently a result of searching for the engine size that maximised thrust to weight ratio. (Or for the very important scientific number 42).
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