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i know they got the data they needed/wanted but can you really call it a success with that ending? on a side note: how much money do they lose whenever they ha

by ffggvv 6y ago

i know they got the data they needed/wanted but can you really call it a success with that ending? on a side note: how much money do they lose whenever they have a crash landing like that?

greedo 6y ago
It depends on the goals of the launch. If they met their goal criteria, and sticking the landing wasn't one of the goals, then it's a success.
- qayxc 6y ago
  I'm pretty sure a successful landing was one of the goals. It just might have been a "nice to have"-kind of goal. During prototyping there's only one type of test that isn't a success: a test that fails for a previously known reason (e.g. repeating a known mistake or some external factor like earthquakes, flooding or weather) and that you learned nothing from.
  - greedo 6y ago
    Elon explicitly tweeted the mission's goals: "Goals are to test 3 engine ascent, body flaps, transition from main to header tanks & landing flip." So the SpaceX team went four for four...
handol 6y ago
I'm sure there's some cost in cleaning up the scrap and repairing any damage to the facility. But it's a prototype, and I think this was the only flight planned for this one.
waiseristy 6y ago
Never heard of a test to destruction?
- qayxc 6y ago
  That's something entirely different, though. Test to destruction/failure is done to check or verify the limits of a systems. This test on the other hand was a test with a low change of complete success and thus failure was an expected and acceptable - but not the intended - outcome.
  - oska 6y ago
    I take your point but if this flight had landed they would have probably kept test flying SN-8 until it did crash. There is really no other use for it.
DylanDmitri 6y ago
They could do more part verification, but it might take twice the time and 3 times the money for the same insights. Just launch some prototypes and see what happens.
_ph_ 6y ago
It is a great success. They launched the Starship on 3 Raptors, most importantly perfectly controlled the descend and correctly executed the flip and vertical landing. If the fuel pressure had been correct, even the landing would have worked, but that is a really small thing to correct. The main thing, and that is why it was a success, was the in-flight control, especially on the descent and before the landing. Only real loss was 3 engines they might have reused otherwise. But as the Starships themselves are extremely cheap to build - the next one is already mostly finished - it was basically considered expendable for the test. Beyond understanding and fixing the fuel pressure issue, they just can proceed with their testing plans as scheduled.
ibraheemdev 6y ago
Elon Musk tweeted this a few weeks ago: > Goals are to test 3 engine ascent, body flaps, transition from main to header tanks & landing flip. Considering they achieved all their goals, I would say it was a success.
- bob33212 6y ago
  Huge Success. This is a prototype. It was going to be thrown away next week regardless. Obviously long term the landing is very important. Just not today.
  - klmadfejno 6y ago
    Would they actually throw it away if it worked flawlessly? Why not try another test?
    - simonh 6y ago
      SN 9 is ready for testing in the next few weeks and has more design changes they need to test, so SN 8 is no longer needed. On the other hand the loss of the engines is a shame. They are by far the most expensive part of the vehicle and could have been used in later vehicles.
mrandish 6y ago
Yes, absolute success. All primary mission objectives achieved successfully AND all but one secondary objective achieved. Launch, ascent, MECO, controlled descent, turn and re-orient with nose thrusters, fire engines, decelerate, position over landing pad, in correct orientation, AND, most importantly, capture all mission telemetry and data until after ground contact. As a mere spectator, I'll add they achieved ALL my additional personal objectives, including: end-to-end live video/audio transmission from multiple onboard and ground tracking cameras, conveniently streamed in the late afternoon for free, near-instant pre and post-test insights direct from Elon via Twitter, AND a perfectly-framed SPECTACULAR live explosion in HD to cap it all off. From my (somewhat self-centered) perspective, how could it have been any more successful? As for your "losing money" question, I'm not sure that's much of a factor with SN8 because it was a test article not expected to probably survive. It didn't even have final or complete flight systems. If it had remained more intact after landing, perhaps they could have reused some raw materials eventually for future test articles but that also requires extensive inspection to re-validate, disassemble and integrate - all of which would consume scarce schedule time, assembly space and the limited time of skilled personnel able to build final Starships. IHMO, SpaceX wisely prioritizes speed and learning over testing costs or PR optics. The biggest unexpected cost may just be the "cleanup on aisle SN8" but they probably didn't expect SN8 would reach the landing pad as on-target as it did and may have budgeted even more time/money for clean-up than they'll need since it was pretty dang tidy for a RUD. I guess an over-water loss might be a bit faster/cheaper to reset but then they would have lost higher priority objectives and we wouldn't have had such a SWEET front-row ticket to the finale :-).
- virgilp 6y ago
  It's not just "cleanup" - they would probably reuse the raptors and maybe batteries/ other stuff too. Losing 3 raptors is probably what hurts the most at this point (but it wasn't unexpected). All in all, the test was most definitely a success.
  - emilecantin 6y ago
    I'm not sure they'd even reuse them, they're still tweaking the design. The Raptors that flew yesterday were probably already outdated; the ones on SN9 are improved versions already.
joshxyz 6y ago
Fair question, I think one of their goals is to maximize the lessons/takeaways they get from minor failures like this and be able to recalibrate effectively on the next launches. Just like bare scientific method of trial and error.
mlindner 6y ago
Listen to one of the engineers who designed part of the rocket. https://twitter.com/PBearATX/status/1336847380499468289 https://twitter.com/PBearATX/status/1336847380499468289
crystalmeph 6y ago
“Fail early, fail often” may actually be cheaper in the long run than never running actual tests until you’ve run enough simulations and analysis to satisfy yourself the test will not fail. If you accept that premise, this test can definitely be viewed as a complete success, since they got telemetry from every phase of operation and know exactly what to improve for the next test.

by ffggvv 6y ago

i know they got the data they needed/wanted but can you really call it a success with that ending? on a side note: how much money do they lose whenever they have a crash landing like that?

greedo 6y ago

It depends on the goals of the launch. If they met their goal criteria, and sticking the landing wasn't one of the goals, then it's a success.

qayxc 6y ago
I'm pretty sure a successful landing was one of the goals. It just might have been a "nice to have"-kind of goal. During prototyping there's only one type of test that isn't a success: a test that fails for a previously known reason (e.g. repeating a known mistake or some external factor like earthquakes, flooding or weather) and that you learned nothing from.
- greedo 6y ago
  Elon explicitly tweeted the mission's goals: "Goals are to test 3 engine ascent, body flaps, transition from main to header tanks & landing flip." So the SpaceX team went four for four...

handol 6y ago

I'm sure there's some cost in cleaning up the scrap and repairing any damage to the facility. But it's a prototype, and I think this was the only flight planned for this one.

waiseristy 6y ago

Never heard of a test to destruction?

qayxc 6y ago
That's something entirely different, though. Test to destruction/failure is done to check or verify the limits of a systems. This test on the other hand was a test with a low change of complete success and thus failure was an expected and acceptable - but not the intended - outcome.
- oska 6y ago
  I take your point but if this flight had landed they would have probably kept test flying SN-8 until it did crash. There is really no other use for it.

DylanDmitri 6y ago

They could do more part verification, but it might take twice the time and 3 times the money for the same insights. Just launch some prototypes and see what happens.

_ph_ 6y ago

It is a great success. They launched the Starship on 3 Raptors, most importantly perfectly controlled the descend and correctly executed the flip and vertical landing. If the fuel pressure had been correct, even the landing would have worked, but that is a really small thing to correct. The main thing, and that is why it was a success, was the in-flight control, especially on the descent and before the landing. Only real loss was 3 engines they might have reused otherwise. But as the Starships themselves are extremely cheap to build - the next one is already mostly finished - it was basically considered expendable for the test. Beyond understanding and fixing the fuel pressure issue, they just can proceed with their testing plans as scheduled.

ibraheemdev 6y ago

Elon Musk tweeted this a few weeks ago: > Goals are to test 3 engine ascent, body flaps, transition from main to header tanks & landing flip. Considering they achieved all their goals, I would say it was a success.

bob33212 6y ago
Huge Success. This is a prototype. It was going to be thrown away next week regardless. Obviously long term the landing is very important. Just not today.
- klmadfejno 6y ago
  Would they actually throw it away if it worked flawlessly? Why not try another test?
  - simonh 6y ago
    SN 9 is ready for testing in the next few weeks and has more design changes they need to test, so SN 8 is no longer needed. On the other hand the loss of the engines is a shame. They are by far the most expensive part of the vehicle and could have been used in later vehicles.

mrandish 6y ago

Yes, absolute success. All primary mission objectives achieved successfully AND all but one secondary objective achieved. Launch, ascent, MECO, controlled descent, turn and re-orient with nose thrusters, fire engines, decelerate, position over landing pad, in correct orientation, AND, most importantly, capture all mission telemetry and data until after ground contact. As a mere spectator, I'll add they achieved ALL my additional personal objectives, including: end-to-end live video/audio transmission from multiple onboard and ground tracking cameras, conveniently streamed in the late afternoon for free, near-instant pre and post-test insights direct from Elon via Twitter, AND a perfectly-framed SPECTACULAR live explosion in HD to cap it all off. From my (somewhat self-centered) perspective, how could it have been any more successful? As for your "losing money" question, I'm not sure that's much of a factor with SN8 because it was a test article not expected to probably survive. It didn't even have final or complete flight systems. If it had remained more intact after landing, perhaps they could have reused some raw materials eventually for future test articles but that also requires extensive inspection to re-validate, disassemble and integrate - all of which would consume scarce schedule time, assembly space and the limited time of skilled personnel able to build final Starships. IHMO, SpaceX wisely prioritizes speed and learning over testing costs or PR optics. The biggest unexpected cost may just be the "cleanup on aisle SN8" but they probably didn't expect SN8 would reach the landing pad as on-target as it did and may have budgeted even more time/money for clean-up than they'll need since it was pretty dang tidy for a RUD. I guess an over-water loss might be a bit faster/cheaper to reset but then they would have lost higher priority objectives and we wouldn't have had such a SWEET front-row ticket to the finale :-).

virgilp 6y ago
It's not just "cleanup" - they would probably reuse the raptors and maybe batteries/ other stuff too. Losing 3 raptors is probably what hurts the most at this point (but it wasn't unexpected). All in all, the test was most definitely a success.
- emilecantin 6y ago
  I'm not sure they'd even reuse them, they're still tweaking the design. The Raptors that flew yesterday were probably already outdated; the ones on SN9 are improved versions already.

joshxyz 6y ago

Fair question, I think one of their goals is to maximize the lessons/takeaways they get from minor failures like this and be able to recalibrate effectively on the next launches. Just like bare scientific method of trial and error.

mlindner 6y ago

Listen to one of the engineers who designed part of the rocket. https://twitter.com/PBearATX/status/1336847380499468289 https://twitter.com/PBearATX/status/1336847380499468289

crystalmeph 6y ago

“Fail early, fail often” may actually be cheaper in the long run than never running actual tests until you’ve run enough simulations and analysis to satisfy yourself the test will not fail. If you accept that premise, this test can definitely be viewed as a complete success, since they got telemetry from every phase of operation and know exactly what to improve for the next test.