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RCgothic

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Everything posted by RCgothic

  1. Economically it might not make much difference whether $ are spent on coffee, SLS, or Falcon Heavies, economic stimulus being economic stimulus, but if what you're interested in is Spaceflight Milestones Achieved then there'll be a vast difference in outcomes depending on which you spend money on.
  2. The 38t to TLI that B1B can do is more than enough to get Orion into LLO with a stretched service module. They should have just come straight to this as the baseline version. Then send the lander on a second launch. 38t doesn't get you 4 people for an extended stay, but it might get you 2 for an extended stay. 38t to TLI is roughly 28t in LLO, nearly twice Apollo. But there's no plan to upgrade the ESM, and they couldn't build SLSs fast enough to support this anyway. "But even a long stay isn't a sustainable presence, that's why we need gateway!" they counter-argue despite gatew
  3. Working an Apollo lander through my spreadsheet (~15t) comes up with about 64t to TLI with Orion, so yeah I agree with your figure. That'd be 155t to LEO with SLS, which isn't on their upgrade path at all. Ironically, uprated Saturn V with F1As could probably have done it, but TBH safety is one of the few things you can't really fault SLS Orion on. Saturn V was probably lucky not to lose a crew, nevermind the crew they almost lost on Apollo.
  4. The difference between what 2 people need for a brief excursion and what 4 people need for an extended stay plus a tonne of cargo retun gets quite large, aye.
  5. Sure, but there were other options between "do it Apollo style" and "do it SLS style", even without considering the launchers that have come along in the mean time. Capsule and lander LLO rendezvous with a cadence of 4 missions/8 launches per year should have been possible if SLS and Orion had actually be designed coherently. If SLS and the ESM were a little bigger (B1B as a base) and/or Orion was a little lighter. EOR was and remains viable, with/without Lunar rendezvous as well. Delta IV Heavy and Atlas V both could have been crew rated with a will. Then the Falcon family came alon
  6. Ouch, basically. Let's assume a lunar module. Apollo Ascent was roughly 2.4t dry for 2 people, so let's assume double that for 4, plus 100% again for an extended stay and a bit more comfort. Roughly 7t. Plus return with 1t of samples. To get back to LLO (1730m/s) takes 7 more tons of propellant at 310 ISP to give a bit of margin for rendezvous (1910m/s) so the ascent stage will weigh 14t landed, 15t on launch, and 8t back in LLO. To land the ascent stage (14t) from LLO plus 1t of cargo might be 21t landed, assuming 6t for the stage dry (again, a little under 3x Apollo). To get there
  7. At least it wasn't one of the flight leaders.
  8. They'll need to actually put a pathfinder on the launch facilities to make sure everything fits. I'd be amazed if the first vehicle out of the factory is a flight article.
  9. Btw, I'd expect a fully expendable starship to have a substantially lighter dry weight. No fins, no heatshield, no header tanks and disposable fairing. At 5% dry mass, disposable starship would be ~62.5t. F9US is 3.9%. Expendable Starship could even be better because of the way square cube works. Expendable Starship may be a fairly niche application for distant destinations once they get orbital refuelling worked out. They absolutely do not want to be expending these things. But it kind of makes sense as an easily acheivable early milestone. Personally if I were Elon I'd like to
  10. Elon has previously agreed a pure tanker with stretched tanks and 9 raptors (6Vac, 3SL) might make sense.
  11. If it had to be in LEO I probably wouldn't bother with solar, I'd go straight to bomb-pumped. Much smaller, much cheaper. One-shot, but you could have multiple. If it absolutely had to be solar-powered, I'd put the solar collector somewhere separate from the weapon and beam the power with a microwave laser or similar.
  12. It'll probably be a dual ASDS landing for the side cores with centre core expended. 15t is comfortably within FH's GTO expendable capability of 26.7t, but enough more than the 8t reusable threshold that being on a sub-GTO trajectory probably won't make enough of a difference. I wonder if using an extended fairing comes with much of a performance penalty?
  13. What happens to the light that comes from this angle?
  14. I'm not sure I completely follow the optics here, but it sounds like a solar powered laser would have more success as a weapon than a mirror.
  15. On Jan 25th it sounds like SLS definitively lost Clipper:
  16. Clipper formally no longer making SLS compatibility efforts. It's likely to be FH:
  17. Wow, a whole tonne. As a separate mission to crew. How ambitious.
  18. As well as picking an alternative satellite in an alternative direction, once the constellation is mature, which should give some protection from passing storms.
  19. That's exactly the sort of situation Starlink is optimal for.
  20. With 1 engine out allowed on ascent and landing, at 2% chance of failure per burn the Starship upper stage would have a 99.4% chance of successful ascent (6 failures in 1000) on 6 engines and a 99.9% chance of a successful landing on 3 engines. That's 7 failures in 1000 due to engines. With 4 engines out allowed on ascent, the Superheavy booster, the Superheavy booster has a 99.98% chance of successful ascent. That's 2 failures in 10,000. Loss of crew due to engines would therefore be 72 in 10,000 missions. The booster landing on 4 engines would land successfully (up to 1 engine
  21. I didn't forget it, it just wasn't relevant to whether a planet can have SSOs or not.
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