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Starship's Third Flight Test [video]

spacex.com

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Re: Starship's Third Flight Test [video]

#331

Post by firebaze »

exDM69 wrote: post #218
neffo wrote: post #196

Earlier quoted context omitted.

You 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.

No, 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.

They do this while performing the burn of the (in this case) 2nd stage. "No, that's inefficient" is misleading, IMHO. They also waste some delta-V by starting the circularization burn a little bit early.

You surely know that, but mathematically it is unavoidable to have a 2nd burn at the apoapsis to have an orbit (with a periapsis > the initial launch altitude, minus gravity and atmospheric losses), albeit it may start earlier (while wasting a slight amount of delta-v).

Re: Starship's Third Flight Test [video]

#332

Post by bandyaboot »

DarmokJalad1701 wrote: post #313
bdamm wrote: post #299

Earlier quoted context omitted.

Yes, but the point was that they can't launch starlinks or just about any commercially meaningful payload until they are reliably in orbit, and they can't reliably get into orbit until they demonstrate at least one relight, because they need to reliably re-enter the atmosphere for the reusability tests. So they are at least one more launch away from launching starlinks.

> commercially meaningful payload until they are reliably in orbit, Which then can do without a relight. > and they can't reliably get into orbit until they demonstrate at least one re-light And part of testing deorbit/landing capability includes testing that they can relight the engine. So they could launch the next one with Starlinks (possibly test articles of those as well since no full-size V2 satellites have bee…

They won’t put starship into orbit until they can test relight. They won’t risk, nor would they be allowed to risk putting it up there without a demonstrated ability to bring it back down in a controlled manner.

Re: Starship's Third Flight Test [video]

#333

Post by mrandish »

fernandotakai wrote: post #98

those plasma views when starship was coming into atmosphere were absolutely mind blowing. it makes a lot of sense to use starlink for this, but it never ever crossed my mind.

Indeed! I just want to thank SpaceX for giving me yet another "This looks like insane Hollywood special effects but it's real" moment.

Re: Starship's Third Flight Test [video]

#334

Post by f-securus »

pclmulqdq wrote: post #330
HeyLaughingBoy wrote: post #323

Earlier quoted context omitted.

When 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.

If 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.

Holy 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.

Re: Starship's Third Flight Test [video]

#335

Post by zer0c00ler »

pclmulqdq wrote: post #330
HeyLaughingBoy wrote: post #323

Earlier quoted context omitted.

When 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.

If 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.

I think each test served exactly its purpose and it's incredible to see the rapid progress. Unclear why you believe the first two were not a success at all? Did you expect a novel vehicle like this would just work the first time?

Re: Starship's Third Flight Test [video]

#336

Post by Shawnj2 »

93po wrote: post #293
bane wrote: post #280

Earlier quoted context omitted.

Now 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.

JWST would also be incredibly less expensive if it didn't have to do the very complex folding required by smaller rockets

Launching JWST on Starship would still be incredibly expensive because JWST is at the Lagrange point on the other side of the moon and 1 starship needs like 30 other starships to fuel it to get there

Re: Starship's Third Flight Test [video]

#337

Post by tempaway444641 »

elihu wrote: post #322
tempaway444641 wrote: post #221

Earlier quoted context omitted.

It does look like it came down rather fast. Engines only partially re-lit. About 34min in this video https://www.youtube.com/watch?v=NWM1NQ1tZEU&t=2112s

I think that's the ascent burn. It doesn't look like the engines re-lit at all for the descent. (I imagine they aren't supposed to light until they're a lot closer to the ground than they were when the video was lost.)

At altitude 22km superheavy was moving at 4310 kmh (34:18 in linked video) speed then dropped continually, at 34:45 in the video the icons show that 3 engines were lit, altitude was 1km and speed was 1300 kmh. At 34:49 you can see flames, speed continues to drop, then you see the sea rushing up, then it cuts

Re: Starship's Third Flight Test [video]

#338

Post by bandyaboot »

pclmulqdq wrote: post #330
HeyLaughingBoy wrote: post #323

Earlier quoted context omitted.

When 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.

If 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.

The test flights have been right in line with how spacex does development and testing. I’m confident that everyone involved with granting them that money knew this going in.

Re: Starship's Third Flight Test [video]

#339

Post by 2OEH8eoCRo0 »

f-securus wrote: post #334
pclmulqdq wrote: post #330

Earlier quoted context omitted.

If 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.

Holy 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.

They haven't gotten to the revolutionary part yet (fuel tankers in orbit, raptor relight, reusable first stage, reentry).

Re: Starship's Third Flight Test [video]

#340

Post by MostlyStable »

hagbard_c wrote: post #251
gameshot911 wrote: post #240

Earlier quoted context omitted.

I'm not sure the payload doors successfully opened and closed. Anyone have more details?

I 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.

Scott 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

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