Just a general question, does anyone here have any reason to think that the LAS on the Dragon would not have been sufficient to pull a crew away from the failing Amos-6 rocket?
Because the capsule re-enters at a positive angle of attack, to generate lift. The heat shield is symmetric around the "nose" of the capsule as it re-enters "nose up".EDIT: actually, probably symmetric about the zero angle-of-attack point (ie, oncoming airflow). Presumably we'd call the geometric center of the heat shield the "nose", and it's not symmetric about that.
Thanks, johnny and Lars, the video overlays do seem convincing to me, however, I'm in an argument elsewhere with someone who is convinced they prove nothing. Specifically, he has said "in order for an abort system to have a chance of working you need advance warning (in the range of at least several seconds) and to get that warning you need to know what you are looking for and as of now SpaceX doesn’t."So since SpaceX has not yet determined what the cause of the anomaly was, the computer system would not have been able to recognize that it should initiate a launch abort. He is also convinced that a launch abort system needs "several seconds" to initiate. He also seems to believe the capsule must be going supersonic within 0.1 seconds in order to get safely away from the fireball.
Quote from: whitelancer64 on 10/04/2016 07:58 pmThanks, johnny and Lars, the video overlays do seem convincing to me, however, I'm in an argument elsewhere with someone who is convinced they prove nothing. Specifically, he has said "in order for an abort system to have a chance of working you need advance warning (in the range of at least several seconds) and to get that warning you need to know what you are looking for and as of now SpaceX doesn’t."So since SpaceX has not yet determined what the cause of the anomaly was, the computer system would not have been able to recognize that it should initiate a launch abort. He is also convinced that a launch abort system needs "several seconds" to initiate. He also seems to believe the capsule must be going supersonic within 0.1 seconds in order to get safely away from the fireball.I don't think an abort system would have much of a problem realizing that the upper stage it is sitting on is disintegrating. All power and communication lines have just been severed, and if that isn't a signal to abort - what is? And the advance warning of several seconds is just B.S., Super Draco engines can go to full thrust very quickly - on the order of milliseconds, not seconds.
Quote from: Lars-J on 10/04/2016 08:03 pmQuote from: whitelancer64 on 10/04/2016 07:58 pmThanks, johnny and Lars, the video overlays do seem convincing to me, however, I'm in an argument elsewhere with someone who is convinced they prove nothing. Specifically, he has said "in order for an abort system to have a chance of working you need advance warning (in the range of at least several seconds) and to get that warning you need to know what you are looking for and as of now SpaceX doesn’t."So since SpaceX has not yet determined what the cause of the anomaly was, the computer system would not have been able to recognize that it should initiate a launch abort. He is also convinced that a launch abort system needs "several seconds" to initiate. He also seems to believe the capsule must be going supersonic within 0.1 seconds in order to get safely away from the fireball.I don't think an abort system would have much of a problem realizing that the upper stage it is sitting on is disintegrating. All power and communication lines have just been severed, and if that isn't a signal to abort - what is? And the advance warning of several seconds is just B.S., Super Draco engines can go to full thrust very quickly - on the order of milliseconds, not seconds.That is precisely what I've been saying! To no avail, it seems. I should probably just let this one go. And yes, a report from a few years back said from the signal to ignite to full thrust of the SuperDracos is less than 100 miliseconds. I've mentioned that, too, but again, deaf ears.
Specifically, he has said "in order for an abort system to have a chance of working you need advance warning (in the range of at least several seconds) and to get that warning you need to know what you are looking for and as of now SpaceX doesn’t."
Welcome to Jim's world.
Quote from: DavidH on 10/04/2016 10:50 pmWelcome to Jim's world.That is high praise! Thank you very much.
Quote from: whitelancer64 on 10/04/2016 07:58 pmThanks, johnny and Lars, the video overlays do seem convincing to me, however, I'm in an argument elsewhere with someone who is convinced they prove nothing. Specifically, he has said "in order for an abort system to have a chance of working you need advance warning (in the range of at least several seconds) and to get that warning you need to know what you are looking for and as of now SpaceX doesn’t."So since SpaceX has not yet determined what the cause of the anomaly was, the computer system would not have been able to recognize that it should initiate a launch abort. He is also convinced that a launch abort system needs "several seconds" to initiate. He also seems to believe the capsule must be going supersonic within 0.1 seconds in order to get safely away from the fireball.It wasn't an explosion, and there no particular reason why a crewed dragon would need to get out of there instantly.Dragon could have sat on the TEL for at least as long as the payload fairing did (about 3 seconds if I recall correctly) with no adverse affects to the crew. That's a fairly benign environment compared to re-entry.
He is also convinced that a launch abort system needs "several seconds" to initiate. He also seems to believe the capsule must be going supersonic within 0.1 seconds in order to get safely away from the fireball.
Quote from: whitelancer64 on 10/04/2016 07:58 pmHe is also convinced that a launch abort system needs "several seconds" to initiate. He also seems to believe the capsule must be going supersonic within 0.1 seconds in order to get safely away from the fireball.It's probably like talking to a brick wall, But you might point out :(1) The Little Joe Apollo LES test fired on it's own when the rocket broke up in flight unexpectedly and did so fast enough to work properly.(2) An escape system that has to go 0-supersonic in a tenth of a second is pretty much guaranteed to be fatal. If this is needed there's no survivable way out anyways.
Think you can remove "pretty much" - that's well over 300 g, aka pink jelly territory
Quote from: eriblo on 10/11/2016 09:10 pmThink you can remove "pretty much" - that's well over 300 g, aka pink jelly territory For at least it will be contained in spacesuits, so the capsule won't be stained.