Quote from: the_other_Doug on 08/18/2015 06:04 pmKim Keller has stated here that since the S1 engines were observed to continue to fire right through the RUD of S2, that the FTS was never activated, because the first thing the FTS does is shut down the engines. Since the engines were observed to continue to fire right up to the point where S1 came apart, he concluded that the FTS never activated. Since Kim is one of the stalwart pros here, I tend to believe him.Yup, that's plenty good enough for me. Now that you mention it, I do recall that discussion. So outside a direct contradiction from SpaceX, I think that is settled. Now I have heard that there are break-wires between the stages that are supposed to trigger the FTS. So, should have the FTS fired? Is this a secondary failure that no one is talking about, or is the first stage supposed to ignore a disintegrated second stage?
Kim Keller has stated here that since the S1 engines were observed to continue to fire right through the RUD of S2, that the FTS was never activated, because the first thing the FTS does is shut down the engines. Since the engines were observed to continue to fire right up to the point where S1 came apart, he concluded that the FTS never activated. Since Kim is one of the stalwart pros here, I tend to believe him.
That depends on how the break-wires work. Is it loss of communications with the second stage avionics or a physical break between the stages? If the latter, then maybe there was enough of the second stage still attach to pass a continuity check.
If musk has another press conference following the official determination of cause, I hope this is a question that gets asked. I would love for Musk to clarify what the first stage was doing and "thinking" as the second stage ceased to exist, and if they have programmed in new contingencies to the first stage avionics should something like this happen again.
Reprogram the first stage to do what? The thing kept flying like a champ even as S2 was disintegrating, and the guidance system looked rock solid. Hard to improve on that.
Quote from: Kabloona on 08/19/2015 02:33 pmReprogram the first stage to do what? The thing kept flying like a champ even as S2 was disintegrating, and the guidance system looked rock solid. Hard to improve on that.Reprogram to stop accelerating and putting the escaping Dragon in danger as is supposed to happen in crewed flight.
Quote from: guckyfan on 08/19/2015 02:48 pmQuote from: Kabloona on 08/19/2015 02:33 pmReprogram the first stage to do what? The thing kept flying like a champ even as S2 was disintegrating, and the guidance system looked rock solid. Hard to improve on that.Reprogram to stop accelerating and putting the escaping Dragon in danger as is supposed to happen in crewed flight.PreferToLurk was talking about "something like this happening again," which I took to mean on uncrewed cargo flights. On CRS-7, stage 1 did exactly what it was supposed to do, keep flying as long as safely possible.You're talking about launch abort software that will be active when crewed Dragon comes on line, which I agree would hopefully behave differently. Meanwhile, I fail to see the need to "program new contingencies" on S1 for cargo flights. Evidently cargo Dragon will get a software change for chute deployment in case of premature separation. Seems to me that's all they need to do for now.
Quote from: PreferToLurk on 08/19/2015 01:39 pmIf musk has another press conference following the official determination of cause, I hope this is a question that gets asked. I would love for Musk to clarify what the first stage was doing and "thinking" as the second stage ceased to exist, and if they have programmed in new contingencies to the first stage avionics should something like this happen again.Reprogram the first stage to do what? The thing kept flying like a champ even as S2 was disintegrating, and the guidance system looked rock solid. You want the vehicle to keep flying no matter what, until FTS command is issued. It did. Hard to improve on that.
Is it time to start some sort of a pool to guess at the announced/actual return to flight date?
Is it time to start some sort of a pool to guess at the announced/actual return to flight date?Enjoy, Matthew.
Has it ever happened before that a second stage disintegrates during nominal first stage performance?
Quote from: guckyfan on 08/19/2015 04:57 pmHas it ever happened before that a second stage disintegrates during nominal first stage performance?Yes. First flight of Atlas Centaur.
Quote from: Steven Pietrobon on 08/20/2015 06:54 amQuote from: guckyfan on 08/19/2015 04:57 pmHas it ever happened before that a second stage disintegrates during nominal first stage performance?Yes. First flight of Atlas Centaur.Now that was a bit eerily similar, especially with the large dark object falling away early on, just like Dragon in the F9 footage.
I guess all security protocols are reviewed/changed,