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The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake
by DarmokJalad1701 3y ago
The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake. They can refine re-usability while flying payloads.
- enraged_camel 3y agoI think they also successfully demoed in-space fuel transfer.
- xondono 3y agoFuel transfer with what? That would require things like docking
- Tor3 3y agoThey transferred something like 10 tonnes of fuel from one end of the ship to the other.
- hagbard_c 3y agoTransfer internally between tanks in the bottom and top of the ship. This was one of the planned tests, I have not heard whether it was accomplished though.
- dotnet00 3y agoThere was a callout saying that it was successful. Edit: On the other hand tweets from Gwynne suggest that they still need to review the data to see if it was a success.
- enraged_camel 3y agoThey performed an in-ship fuel transfer, from one chamber to another. My understanding is that this is a very important pre-requisite for an actual transfer from one ship to another, because of the need to keep the fuel at cryogenic temperatures during the transfer, which is apparently not easy. Last time it was done was decades ago, but in kilograms. SpaceX just demoed a transfer of tons of fuel.
- extraduder_ire 3y agoBigger problem than keeping it cryogenic is getting it to one side of the tank while in orbit, so the pumps don't run "dry". Harder than just doing an ullage burn first too, because moving that amount of mass around also moves the vehicle.
- cchance 3y agoThey used tanks inside the ship to transfer from 1 to another to prove the process, was discussed and called out as success, and talked about many times before the flight
- deleted 3y ago[deleted]
- ajross 3y agoNot quite: the apogee burn they had planned didn't happen (no word as to why yet), so the ship didn't technically demonstrate the capability reach orbit. It came back down in the Indian ocean on its original suborbital trajectory, essentially like an ICBM.
- DarmokJalad1701 3y agoThat is a matter of the trajectory they chose on purpose for this test flight. A different flight profile would have given them a perigee above the atmosphere (rather than -50 km)
- Laremere 3y agoParent's (correct) point is that it isn't a matter of the ascent trajectory. They can't leave the Starship up in orbit, and where it reenters needs to be controlled.
- DarmokJalad1701 3y ago> They can't leave the Starship up in orbit, and where it reenters needs to be controlled. Why? Plenty of boosters re-enter uncontrolled and burn up all the time.
- golol 3y agoOk so they could leave Starship in orbit and launch payloads like that. The idea however is to launch payloads WHILE testing reentry and landing. This requires an engine relight in orbit.
- DarmokJalad1701 3y ago> WHILE testing reentry and landing. > This requires an engine relight in orbit. The latter is part of the test at this point of development
- 3y ago
- travisgriggs 3y agoI wouldn’t classify the re-entry survival problem as icing. But otherwise, I agree with you.
- johnyzee 3y agoYeah, breaking up in-air during re-entry (at 65 km going by last telemetry) seems like a potential big issue to fix.
- tempaway444641 3y agoThe point they were trying to make is that getting up is MVP, getting back down can be figured out later
- dotnet00 3y agoOP's point is that the tests become a bit cheaper and a bit easier to get licenses for since they can get to orbit and can deploy Starlinks. The reentry problems of course have to be fixed, but the FAA mishap investigation will involve fewer delays, just like how Falcon 9 was able to keep flying, attempting landings without having to wait for a mishap investigation to finish every time a landing failed.
- usrusr 3y agoIirc F9 had its main challenge in that final suicide burn. Usually the boosters made it there just fine and then "only" failed to get the parameters aligned just right. Based on what we saw today, the main chokepoint for Starship might be right in that hot reentry telemetry blind spot. Debugging without logs.
- dotnet00 3y agoIt sounded like they might have had flight data recorders on-board which might have survived through reentry with telemetry. If so, they'd have some logs, but yes, figuring out reentry will likely be the main challenge for now, not only is it hard to debug, even getting to it requires everything else to go more or less perfectly.
- golol 3y agoOne technical modification: They need engine relight in orbit to work to deliver payloads, otherwise Starship will stay in orbit and they can not test reentry.
- neffo 3y agoYou need a second burn just to enter orbit. You burn at the top of the sub-orbital arc (opposite side of the earth) to enter orbit.
- exDM69 3y agoNo, that's inefficient and real spacecraft don't do that for typical low earth orbits. Works in Kerbal Space Program, though. Normal orbital insertion is a single burn to orbit (with staging). With the correct initial roll and pitch, the spacecraft follows a perfect gravity turn and ends up in a near circular orbit at main engine cut off.
- dotancohen 3y agoDo they typically burn softly until near apogee, then put on the power until raising the orbit on the other side to their current altitude? In KSP, I can easily get an orbit on a single burn (with staging) but getting it circular obviously requires adding energy at apogee.
- exDM69 3y agoNo, most rocket engines have quite limited amount of throttle capability and run near maximum thrust until cutoff. The rocket yaws and pitches in the first seconds of flight while the vehicle is still subsonic, then flies a gravity turn trajectory at zero angle of attack (facing the direction of travel) at near maximum thrust. Any errors accumulated during early part of the flight will be corrected by adjusting the timing of the second stage cutoff based on radar tracking. The initial pitch over is just a few degrees off vertical, but must be precise to a fraction of a degree (KSP tolerances are higher due to small planet). You can get a pretty good circular orbit in Kerbal Space Program with one burn if you do a few attempts and trial and error binary search for the optimal initial pitchover angle, but it's very difficult to do without throttling the 2nd stage burn. If I recall correctly, the MechJeb mod can do a precise single burn to orbit.
- gameshot911 3y agoI'm not sure the payload doors successfully opened and closed. Anyone have more details?
- hagbard_c 3y agoI heard the announcement about the door opening and saw - what I assume to be - live images from the inside which showed the door first opened, then closed so it seems that test worked.
- hagbard_c 3y agoHere's an evaluation of things going wrong on the flight by three 'Youtube space flight watchers' (Fraser Cain, Scott Manley and Marcus House) including possible mishaps with the cargo door: https://www.youtube.com/watch?v=EVic941kQ44 https://www.youtube.com/watch?v=EVic941kQ44
- MostlyStable 3y agoScott Manley seems to believe that there was some kind of malfunction with the doors[0]. I couldn't really tell from the video, but he certainly knows a hell of a lot more in this domain than I do. He does agree that overall the test was highly successful though. [0]https://youtu.be/8htMpR7mnaM?t=512 https://youtu.be/8htMpR7mnaM?t=512
- bane 3y agoHere's a fun thought, how many Starship launches would it take to put the equivalent mass of the ISS up in the same orbit?
- DarmokJalad1701 3y agoThe ISS weighs ~420 metric tons. That is 2-3 expendable launches or 3-4 reusable ones.
- GeoAtreides 3y agoJesus Christ, that really puts it into perspective what a game changer starship is
- bane 3y agoNow do the same calculation in units of hubble space telescope and james webb space telescope masses. Then look at expected reusable launch cost and figure out how many HSTs or JWSTs we could have put in orbit for the same cost.
- 93po 3y agoJWST would also be incredibly less expensive if it didn't have to do the very complex folding required by smaller rockets
- Retric 3y agoJWST would still have been an extremely novel and therefore expensive on Spaceship. We just don't build anything that uses that kind of sun shield or those sensors etc and everything needs to work on one shot, thus serious engineering effort.
- Teever 3y agoWith Starship flights it should be the right combination of cheap enough, frequent enough, and big enough to enable whole new paradigms of construction in space. We'll be able to design modular space telescopes that benefit from economies of scale, so that we'll be shipping up the sun shield in separate pieces anyways so if any particular one is lost that's okay we'll have an assembly line to produce more.
- rtkwe 3y agoBig things they still need to hit are soft splashdown of both stages because recovery and reuse are critical to the economics of Starship. From the stream it looks like they had barely any engines light during the landing burn and I could see several missing tiles on the second stage. Way fewer were missing though which is a bonus, last time they were visibly missing a lot of tiles even before they lost the stage.
- jkjkjjjkjkj 3y agoWell, the second stage definitely needs to survive re-entry if it wants to carry passengers. But it seems to work as-is for orbital cargo.
- mgiampapa 3y agoPassenger rating isn't even in the cards for Starship for a long time. You ride to LEO on a Falcon-9 with a proven track record for the foreseeable future.
- avmich 3y ago"Foreseeable" is roughly "five years"? Starship HLS (Human Landing System) is currently planned to land on the Moon, with people, in 2026. It may very well slip a year, two or three - but landing on the Moon this decade still seems quite possible. Or you consider "passengers" different enough than "crew"?
- mgiampapa 3y agoYes, landing on the Moon without an atmosphere is vastly different from orbital flight on earth and has an entirely different risk profile.
- grecy 3y agoInteresting Asterix on that is the humans will only be on Starship from Lunar orbit down to the moon surface and then back to lunar orbit again. No humans aboard during Starship launch, transit to and from the moon or re-entry. (For completeness, humans will do all that other stuff aboard SLS and Orion. Starship literally only ferries them down the moon and back up again)
- avmich 3y agoYes, but HLS is just one example. In, say, ten years it may look very possible that Starships with people will fly on LEO. Is it beyond foreseeable future?.. I just don't understand why such a pessimistic estimate.
- kristianp 3y agoMaybe the words "success" and "failure" are too difficult to shoehorn into describing these tests, especially with the first two tests. "Great progress" is a good intermediate.
- HeyLaughingBoy 3y agoWhen you write a test case, you define what "Passed" means. If this test flight overall meets SpaceX's definition of "Passed", then it was a success, regardless of what anyone else thinks it should mean.
- pclmulqdq 3y agoIf your test case for left pad passes when it outputs a string of the right length, your boss is going to judge whether it's a good test case. Since this is all being done on federal grant money, it's legitimate to have higher expectations. This test was good, though - the previous two were disappointing.
- f-securus 3y agoHoly cow. How are people downplaying something so revolutionary. Without those other tests SpaceX wouldn’t have done what it did today and they show progress each step. They are doing what nasa couldn’t (send stuff to space orders of magnitude cheaper) because they aren’t afraid to blow stuff up.
- 2OEH8eoCRo0 3y agoThey haven't gotten to the revolutionary part yet (fuel tankers in orbit, raptor relight, reusable first stage, reentry).
- f-securus 3y agoRe-using rockets isn't revolutionary?
- senectus1 3y agothe open and close of the payload doors was a failure. Not that i think its a big deal... but its important to acknowledge failures so we can learn from them.