adam525i (Forum Supporter) said:
In reply to alfadriver (Forum Supporter) :
As SN8 blew to pieces, SN9 was almost ready to roll out of the assembly building (in fact it was leaning on it, whoops), as SN9 blew to pieces SN10 was on the pad a couple hundred feet away.
This landing has nothing to do with Falcon's landings (which still aren't 100% successful). Different vehicle, different engines and completely different flight profile. The goal of course is to have a vehicle in one piece afterwards but based on how they are pushing these things out I don't think there was any expectation of that happening on the first flight. If it were NASA yes, they take years upon years to hopefully do it right once, SpaceX is going the other way trying to shrink the development window with some scrap stainless steel along the way.
Different, got it, In every way.
Except for the space engineers working on the project. Again, these guys have done landings, many times, So the odds of the plans including further tests of SN8 and 9 are almost 100%. Which means two planned test were were lost, and that is a big deal. Having lived in a world were testing is a lot easier, I know exactly how devastating to a program when there's a significant loss in the test plan.
Sweet! Can't wait to see the actual SpaceX footage of the second launch of SN10 
Uhhhmmm.... if you stopped looking... you might want to look again.
Big "bada boom"
alfadriver (Forum Supporter) said:
adam525i (Forum Supporter) said:
In reply to alfadriver (Forum Supporter) :
As SN8 blew to pieces, SN9 was almost ready to roll out of the assembly building (in fact it was leaning on it, whoops), as SN9 blew to pieces SN10 was on the pad a couple hundred feet away.
This landing has nothing to do with Falcon's landings (which still aren't 100% successful). Different vehicle, different engines and completely different flight profile. The goal of course is to have a vehicle in one piece afterwards but based on how they are pushing these things out I don't think there was any expectation of that happening on the first flight. If it were NASA yes, they take years upon years to hopefully do it right once, SpaceX is going the other way trying to shrink the development window with some scrap stainless steel along the way.
Different, got it, In every way.
Except for the space engineers working on the project. Again, these guys have done landings, many times, So the odds of the plans including further tests of SN8 and 9 are almost 100%. Which means two planned test were were lost, and that is a big deal. Having lived in a world were testing is a lot easier, I know exactly how devastating to a program when there's a significant loss in the test plan.
But they're going into the test with only a 60% expectation of the landing. Everyone else throws the rocket away after a test flight. Sure, SpaceX has landed more rockets than everyone else put together several times over, but it's still really hard with almost no margin for error. It's not the landing that's hard here, it's the flip. And you can't test the flip without flying the rocket.
And it looks like this one isn't going to be doing any more flights.
In reply to sobe_death :
It didn't get very high lol
These guys build replacement test vehicles faster than a Spec Miata racer preps back up cars lol
Stuck the landing this time!
Stuck the landing.... then exploded...
I mean, who can say that hasn't happened them also?
Landing for the adult side of your brain, big explosion for the little kid side.
Big step forward. Roll out SN11!
Some pics from it's glory... minutes...
Seems like most everything worked good. Looks like that landing gear came out, but a bit hot on the landing. Someone needs to tweak a digit here or there. Maybe it landed heavier then they calculated? It looks like it might have not been vertical on touchdown?
In reply to adam525i (Forum Supporter) :
IDK, it cleared at least its' own height!
In reply to sobe_death :
In the traditional sense it's Houston's problem at that point :)
In reply to Keith Tanner :
Yea, I know S-X is the only one landing and reusing. And I'm betting that Elon Musk has made sure that future tests were based on good landings. That's all I'm saying. These write offs prevented some testing, and that's a big deal.
In reply to aircooled :
I turned off the feed to early! It did look a little toasty and had a bit of a lean after touchdown.
alfadriver (Forum Supporter) said:
In reply to Keith Tanner :
Yea, I know S-X is the only one landing and reusing. And I'm betting that Elon Musk has made sure that future tests were based on good landings. That's all I'm saying. These write offs prevented some testing, and that's a big deal.
They had a couple of test hops with earlier vehicles that landed successfully using more conventional methods. I don't think they ever flew one more than once even though it should have been completely possible. In fact, the SN8/SN9 tests were so successful in their minds that they actually scrapped a couple of vehicles that were in production. In a few more iterations, they might want to refly, but they're not there yet.
So I don't think these tests are necessarily preventing all that much. Even if they did manage to land it in reusable form, there's no guarantee it would have ever flown again as they're basically obsolete when they roll out of the shed. Remember, SpaceX isn't just building a spaceship, they're building a factory to build spaceships. So putting a new one together is actually good practice.
is this just a step forward from landing them on the barge ?
I wonder if the first manned one that they try to land this way will be over land or on the barge ?
In reply to Keith Tanner :
Just want to point out, the "it was just fine" is the line Space X is telling the public.
And having worked for a large corporation for so long, forgive me for calling BS when they claim a write off is perfectly fine.
The fact that they had a start up and shut down earlier in the day only to fly later pretty much yells that this was reusable. Even if it was only a ground based engine test, it was going to be used again. That test is lost, or at least delayed. That's a big deal.
Your corporation was in a mature industry chasing small incremental changes, quite a difference. Your prototypes were much closer to established designs so there was a lot of baseline data to work from.
The fact that the engines could be restarted after an abort just means that the engines were built for multiple starts, as they were. Those engines could have been recovered for another test, sure. But they're also significantly less expensive than any others in the industry. Had they been a few SLS engines, that would sting.
I think the real loss to the engineers is the inability to examine any components that might have been damaged in the explosion. So it's not a loss of future tests that's the problem, it's a potential loss of data that's going to hurt. But they also learned a new failure mode, and they never have the same failure twice.
What's amazing about this launch today is that it included a new concept in relighting and initiating the flip. Which was suggested, planned and put into practice in a month. Yes, the touchdown was a little harder than ideal and/or something went wrong with the legs that led to LOV, but that's an incredible pace of progress.
Keith Tanner said:
What's amazing about this launch today is that it included a new concept in relighting and initiating the flip. Which was suggested, planned and put into practice in a month. Yes, the touchdown was a little harder than ideal and/or something went wrong with the legs that led to LOV, but that's an incredible pace of progress.
???
That concept was part of SN8 and 9. During the righting phase in SN8, it blew up (IIRC one of the engines didn't re-light), and SN9, it was not quite vertical. Maybe I need to look back on those launches, but I very much remember it laying on it's side as it came to earth. And then the engines fired starting to make it vertical again for landing.
Actually, that's not quite right- at 6:34 into the launch of SN8, it went upright, but one motor was not powerful enough for it to stop the momentum- 1:54:47 of this video https://www.youtube.com/watch?v=ap-BkkrRg-o&ab_channel=SpaceX
And the same thing happened for SN9, almost at the same moment relative to the launch- 6:26- (11:53 of this https://www.youtube.com/watch?v=_zZ7fIkpBgs&ab_channel=SpaceX)
Keith Tanner said:
Your corporation was in a mature industry chasing small incremental changes, quite a difference. Your prototypes were much closer to established designs so there was a lot of baseline data to work from.
The fact that the engines could be restarted after an abort just means that the engines were built for multiple starts, as they were. Those engines could have been recovered for another test, sure. But they're also significantly less expensive than any others in the industry. Had they been a few SLS engines, that would sting.
I think the real loss to the engineers is the inability to examine any components that might have been damaged in the explosion. So it's not a loss of future tests that's the problem, it's a potential loss of data that's going to hurt. But they also learned a new failure mode, and they never have the same failure twice.
We will just have to agree to disagree. I will look at these incidents as a very serious hit to the test plan.
This isn't to put down Space X or their engineers at all- just that there will be an impact to the test plan.
The thing to remember is that the main objective of this test plan for SN10 was (as with SN9 and 8) to collect data on atmospheric maneuvering a huge tube at subsonic reentry speeds. This critical dataset begins after the hover/gimball at the first flip maneuver, includes belly flop and flap surface actuation schemes, as well as ballast transfers between the internal tanks, and finally the second relight and flip. Mission accomplished. There are always secondary and tertiary objectives in these test plans, such as sticking the landing and evaluating the ablative tiles on the different surfaces of the Starship, but SpaceX has made it verbally clear all through the Falcon 9 and Heavy testing that they could crash every single rocket during testing, and still be printing money. Sure, it would have been nice to have a vehicle to inspect, but you don't always get your entire wish list. Sticking a landing may have accelerated future test plans, though I highly doubt that it has set them back internally during this development.
SpaceX is not on a mission to reuse rockets, they are on a mission to significantly reduce the cost-to-orbit. The way they do this is by, yes, reusing vehicles, but also they have made incredible leaps to rocket motor design, efficiency, and operational reliability by trying wild ideas that have often ended with a boom. For example, the Falcon Heavy unit flyaway cost is approximately $1,500/kg to orbit while the US' next closest heavy lift option is the Delta IV Heavy at $11,600/kg. I'd call that a significant improvement.
