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mikegarrison

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Everything posted by mikegarrison

  1. There are payloads that a single SLS can launch but no number of F9s can launch.
  2. That's not the issue. I mean, rockets now have real-time computer control that allows them to land! Dealing with the thrust imbalance is not the difficulty. The concern is something like a fire or an uncontained turbo-machinery failure that sends shrapnel into the neighboring engines. We've seen in both launches now that engines start dropping out after the engines next to them drop out, which is extremely concerning.
  3. It all depends on what *kind* of engine failure. There are many failure modes where one engine failing does not particularly risk a cascade, but there are others where it does.
  4. Seems obvious to me that landing is still the biggest risk item for Starship/SH, but of course landing is optional (for now). But the risk item that has bothered me from the start that still seems like it my be plaguing them is the large number of engines. More engines = more redundant *unless* their failure modes are not independent. And it has always concerned me that so many engines, so close, without heavy (and space-consuming) armor between them, is a huge risk for fratricidal cascading engine failures. That means more engines = less reliability, rather than more reliability. We'll see.
  5. My kerbals are too busy playing Baldur's Gate 3 to celebrate this year.
  6. Yes, a year or two ago I remember standing outside my house in the cold on the rare clear winter in the Seattle area, waiting for the ISS to pass over. When it did, there was no mistaking it for anything else.
  7. I am not saying SpaceX is going bankrupt. But that being said, the size of the company is no guarantee against going bankrupt. In fact, it can mean you do so quite quickly. Bigger company means more spending means that you can rack up debts even more quickly.
  8. Yes, obviously if it increases the percentage chances of success, then delay or slow down the rotation. I was just reacting to the suggestion that the only reason they were doing it quickly was to show off. This (almost) can't possibly be true. The claims that were being tossed around was that the cost per flight would ultimately be lower than F9 due to a substantial increase in reusability. A claim that I found dubious. Consider, for instance, prop-fans v. high-bypass turbofans. People were predicting things like a 50% increase in efficiency from the prop-fans back in the 1980s, but it's been 40 years and the propfans are still not in service. Meanwhile the efficiency of the high-bypass turbofans has almost increased to the point where the propfans were predicted to be, so now for the prop-fans to succeed they need to be competing against the current turbofans, not those of the 1980s. As F9 gets more and more reusable and cheaper and cheaper to fly, SH has to compete against the newer, better F9 costs, not the F9 costs that existed when SH was conceived.
  9. There is no "typical rocket of this size". Every second before they boost back makes it harder to return to landing, and the whole premise of the booster is that it must return to landing.
  10. Water deluge has been used for 50 years, at least. The question is not "how did SpaceX design a water deluge system so quickly?", but rather "why did they think they didn't need one before?"
  11. Coriolis has approximately zero effect on such scales.
  12. Radius of the Earth is more than 6000 km. Even an 8km mountain peak is thus about 0.12% different in height versus sea level. This is why gravity is essentially the same.
  13. With most of the fuel burned, almost certainly the rockets make up the bulk of the remaining mass of the booster.
  14. The ship was not headed for an orbital trajectory anyway, even if it had completed its burn.
  15. If STS had blown up on the first launch in the first stage, and then had blown up again on the second launch in the second stage, absolutely no one would be claiming these were great tests and a great learning experience. The goalposts are different for SpaceX -- among the SpaceX fans, anyway. But among the general population, don't expect the "whatever happens, we learn something" thing to be a popular viewpoint. If the third try works, people will no doubt point to the first two and say, "See? Learning by experimentation works." If the third try fails, people will no doubt be saying, "Three times! This rocket is a disaster!" At least they didn't have the same failures twice.
  16. They are large chunks of metal -- titanium, IIRC. Likely would survive an explosion like that more or less intact.
  17. I'm surprised they didn't reshow the flight. Is there a way to watch a replay?
  18. Hmm. I was busy playing BG3 and forgot this was going to happen. I tuned in, and the second stage was burning. But they said the first stage was destroyed? And then, well, they lost contact with the second stage and said it appeared as if the FTS had activated. That seems like a pretty serious issue -- at that point in the profile shouldn't the FTS be safed?
  19. The rules against political discussions prevent me from answering most of this. I will say that EASA charges applicants a fee for them to do the work required to certify an aerospace vehicle. To the best of my knowledge, FAA does not. Both extensively rely on the companies involved spending their own money to do the testing and analyses that the regulators require. They also both allow companies to pay their own employees to act on behalf of the regulators. In such cases the employees are sworn by law to be acting on behalf of the government and not the company that is paying them.
  20. WIW in the current Congressional environment is precisely nothing at all.
  21. We could discuss funding levels at the FAA, but that would be political.
  22. Got news for you, unfortunately. Eventually the whole universe will be dead. The issue here is not whether humanity will survive infinitely far into the future, because it won't. The issue is whether leaving Earth might delay our species' inevitable extinction or whether it might, instead, hasten it. And if it does something like trigger wars, that might be a real issue. If you can redirect an asteroid away from the Earth, that means you can redirect one toward the Earth, too....
  23. With Musk himself being the one who determines whether they make sense? That's not exactly "regulation". Or maybe just of survivor bias. There are other companies that have tried the "go fast and break stuff" idea that have ended up ... broken. In the great dot-com boom of the late 90s there were a lot of companies that burned through all their cash trying to buy market share for their great internet business idea. Some of them became Amazon and Google. Some of them became Pets.com and Webvan and eToys.com.
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