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Everything posted by CBase

  1. Boca Chica to KSC is 1666km according to google maps. So less than 2h with some businessjet. There are several comercial flights < 6h and of course some dead time until flight leaves, however I doubt a standby businessjet is cheaper than 10h extra wait time. For critical timeframes it is probably cheapest just to get personal on standby to Boca Chica.
  2. , I see OSIRIS-REx support from 21th to 25th: https://airbornescience.nasa.gov/aircraft_detailed_cal/2023-09?aircraft_id=36 Assuming they plan at least 3 days in a row for weather and other issues, they would need to be ready by 18th september or in 9 days. I doubt that. From 26th of october there are 8 days of support as placeholder. Way later than expected, but would be realistic.
  3. From https://arstechnica.com/space/2023/09/faa-says-spacex-has-more-to-do-before-starship-can-fly-again/ This is basically good news: There are no additional actions required that SpaceX didn't already prepare for. So yes I am pretty sure that SpaceX can now proceed to have all 63 actions verified. But I doubt they get FAA to approve all this paperwork within next week. My guess: 2-3 weeks delay
  4. Launch and landing are two different things. Breaking up is exactly the risk you want to avoid. With engines firing during ascent a lot of failures lead to RUD and therefore high danger of breaking up. So you don't want launch trajectories over land. For reentry the failures are breaking up due to aerodynamic forces and material failures due to overheating. And of course powered landing. So I guess @darthgently is right, if they have shown with several sea landings that they won't break on reentry a passive trajectory over land is probably fine.
  5. At what altitude is drag sufficient to slow down starship to 200-300 m/s horizontal speed ? Assuming a low payload could they kind of reverse the entry trajectory high enough in order to keep a good safety margin ? My KSP gut feeling says no, but I never tried RO, so all my intuition for speed and altitude is way off from real vlaues.
  6. So any idea how long FAA will need to evaluate the mishap report ?
  7. For SpaceX the measurement of success is not a positive press release with some senator handshaking for next contract, but flying rockets. The open design and operation of starbase are a strong statement they couldn't care less about hiding stuff. Actually I don't think Elon even cares about your, mine or any public opinion about starship at all. There was recently an article on ars technica about valve failures due to humidity. Simple covers spacegrade engine protection sound like a very Kerbal SpaceX solution, doesn't it ?
  8. I never proposed a full duration static fire, that was some other guy. Just your comment that they don't reach the stable state of engine startup in static fire due to deluge limitations is the point more water could help. And since Raptor is deep throttable iterative testing could target lower stable throttle levels first and then keep increasing it. G-Forces are quite low with the full rocket, so pad tests should be quite close to early flight phase. I thought SpaceX is all about speed, but somehow for booster development they stopped to rethink testing.
  9. So opportunity costs to optimize booster start are some additional water tanks vs. early failures in test flights Seriously I miss the fast testing iterations from early starship. Even small hops of booster would be awesome and probably help to improve startup sequence.
  10. https://arstechnica.com/space/2023/05/a-new-report-finds-nasa-has-spent-an-obscene-amount-of-money-on-sls-propulsion/ has more disturbing details in the article and comment section. Basically it shows that cost+ has only motivation to generate fruitless jobs as long as your paperwork is good enough to explain the problem.
  11. Good point. Are there any kind of information whether it was some problem transmitting the FTS signal (maybe not redudant via starlink ?), processing the signal, igniting the charge or time / pressure for enough structural damage to rip it apart ? Would we have seen the charge going off on the video ? I mean on the test tank it looked pretty obvious. But if it wasn't going off, was dynamic pressure or integrity really an issue ? Or maybe antenna / processing ?
  12. Without knowning the failure modes this is a daring conclusion. However from my professional expierence: Increasing reliablity is hard work but makes no good tweet So we shouldn't think it is not happening, because Elon is not tweeting it.
  13. Actually I don't think they really care about if it is a dedicated launcher or shared ride. Just like I don't care how big a plane is. Customers balance constraints and costs. If ride sharing fixes you on a unfavorable schedule or adds a risk to get the own schedule shifted it must save lot of costs to compensate. That is the true reason why I prefer direct flights, but for half the price I do accept sometimes bad flight times. Works only in limited conditions. Orbital changes are not cheap. But ride sharing requires similar target orbits to work out. That is main selling point of small sat launchers. I do think there will be a big new market for SS/SH launches, but only after less expensive (heavier) sat plattforms are available or business case for bigger volume is established.
  14. okay let's try to wrap up community responses with what Elon said: Engine failures: community/critics: too many, propably by pad damage, needs more testing Elon: 3 at start was accepted, they were off limits, but we prefered to try over scrub. Later on we lost some due to heat shield problems. We have more than we can use right now. HPU / TVC: community/critics: HPU exploded Elon: no comment on HPU, but acknoledges some explosion and loss of TVC side note: TVC is elevtric in most current design (not sure about build boosters) staging: community/critics: too low, aero probs, seperation got stuck Elon: wasn't safe enough to try without TVC, really something we want to get to on next attempt pad damage: critics: huge failure, everybody should have known, SX will learn to build flame trench, like all previous generations did Elon (older response): water cooled steal plate was not ready Elon: high pressure, bending most likely cause for concrete failure. Was not expected, but damage is limited to 8 weeks work. Flame Trench is not needed regulations: critics: environmental damage from conrete everywhere Elon: sand distribution is no big deal, however FTS was not working as intended, communication breakdowns did happen structural: community/critics: no more comments on using "ordinary" steal Elon: working better than expected as observed by unintended stress at end of test money: critics: wasting too much money Elon: 2B/y is fine time: critics: more thought and planing would safe time they now have to spend on cleaning up the mess Elon: we learned at lot and will be the first to be ready for Artemis Did I miss some important point ? So personal I do think Elon is for good reason quite relaxed about the first test flight. Will he propably fail on reaching his ambitious mile stones ? yeah, but propably he will be right to be first one ready for Artemis. By years. Like with crewed ISS flights. Or reusable stages.
  15. @sevenperforce thank you for this great explanation If this wasn't SpaceX, I would think anyone bringing up this manoveur as being completely nuts Do you really think this would have been the case on all latches on all sides ? Visually there was no seperation happing at all. Might be true, but loosing the chance to see latches working if you can still trigger FTS afterwards ? I mean with a off-nominal trajectory it must have been clear to everbody already that they will have to. Sounds just likely.
  16. So how is stage seperation actually supposed to happen ? Both regarding movement and release structure. I can't remember if some pictures showed the connections between SH and SS. I have read something like a spin release, but that would indicate a substantial different stage connection than traditional decouplers.
  17. After some slow motions thrust below pad seamed to build up normal, the delay between cameras was just very high. However there are flames coming from above, which might have been HPU
  18. Actually I have a feeling stress on launch pad was anormal already. They did spin up quite early and long and then after ignition there was rather some detonation than reflected thrust. I noticed in the NASA Specaflight video that flames where way faster upwards than transmission from other cam
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