7 ms·

Well, SpaceX does have a launch escape system, as did past US rockets and the current Soviet/Russian one (https://en.wikipedia.org/wiki/Launch_escape_system htt

by hga 10y ago

Well, SpaceX does have a launch escape system, as did past US rockets and the current Soviet/Russian one (https://en.wikipedia.org/wiki/Launch_escape_system https://en.wikipedia.org/wiki/Launch_escape_system), it's the Shuttle that was anomalous in having no provisions for crew survival if something happened after the first few test flights. Although look at the bottom of that link, operationally they've been a mixed blessing, saving one Soyuz crew, but another one wasn't safed after a scrubbed launch and killed a bunch of pad workers. This stuff is hard, "rocket science" really does deserve its connotations of difficulty, and is inherently dangerous.

sandworm101 10y ago
> Shuttle that was anomalous in having no provisions for crew survival if something happened Shuttle had launch abort modes. There was a dead zone during SRB burn, but the rest of the assent had planned abort modes for saving the crew. https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes
- ceejayoz 10y ago
  Planned, but the bailout method in particular was deemed pretty likely to wind up with a bunch of dead astronauts, as it required unbuckling and making your way to a hatch and jumping out at potentially several times the speed of sound from an out-of-control launch vehicle.
  - kobeya 10y ago
    Not to mention emergency life support requiring active intervention to work. It was like having seat belts that required you to push a button to engage in the event of a crash. Not surprisingly not a single astronaut survived Columbia's depressurization at altitude, because of failure to engage active life support. (A blessing because they had a literal snowballs chance in hell of surviving what followed, but still...)
  - sandworm101 10y ago
    Launch aborts are not an options for any tumbling vehicle. A launch abort from a spinning/tumbling rocket would see the capsule fired strait into the ground. Any out of control vehicle is pretty much a lost cause. Shuttle's abort modes, including the bailouts, were premised on the craft being under control. Given the forces involves, if it wasn't under control it probably was about to disintegrate. But the same is true of spaceX-style capsule launches. Whether parachutes would correct a tumbling capsule, or rip it in half, is an open question. They both need to initiate abort procedures at least a millisecond before the craft departs into uncontrolled flight. (And aborts can be triggered automatically, or by someone on the ground.)
    - XorNot 10y ago
      Launch abort though can be fired well in advance of a rocket tumbling though. There's a pretty narrow recoverable angle throughout the launch, the rocket is lost well before the crew can't be saved.
    - ceejayoz 10y ago
      Spinning's entirely possible to survive. The Saturn missions tested it (and it was a really good test - something went wrong and the rocket actually went out of control) - https://www.youtube.com/watch?v=AqeJzItldSQ https://www.youtube.com/watch?v=AqeJzItldSQ A tumble should be fairly trivial to detect and fire only when the capsule's in its upwards pointing portion of the tumble. Plus, you'd only be firing into the ground if you're pretty early in the launch - the Dragon launch abort only sent it up a kilometer or so. Finally, the launch abort is pretty sensitive - deviating not far off the right direction should trigger it, before a full-on tumble.
  - Sir_Cmpwn 10y ago
    RTLS was also a death wish, turning the boat around at those speeds was likely to destroy it.
- hga 10y ago
  There was a dead zone during SRB burn Those alone made it a serious death trap, if you're designing man-rated systems, you like the big boosters to be liquid fueled because you can turn them off if needed, and in many if not most of the relevant failure modes they'll effectively do that anyway. And getting back to my point, as echoed by others, none of these equal a launch escape system, a "Get me the hell out of here!" system for when things have gone horribly and irretrievably wrong with the main system. Particularly unforgivable when it was billed as a boring space truck, when in reality it needlessly ran on the hairy edge in many of its systems. Add the post-Apollo NASA's public works attitude, and we ended up with NASA killing two shuttles and their crews.
  - digi_owl 10y ago
    Best i recall, NASA wanted liquid boosters etc, but congress nixed it for pork barrel reasons.
    - hga 10y ago
      In an analysis published in Science that I read, the biggest driver was development cost. SRBs, in fact, the kludge of the big tank, were all done to minimize that, while drastically driving up operational costs, which, of course, were several elections down the road and sort of hidden/not entirely undesired for what had become almost entirely a public works program. By the same token, I heard first hand from the guy who developed the reentry vehicle that the crazy scheme of Apollo which left us with no operational hardware off the earth was done because it spent "a billion" (8 billion in 2016 dollars) more in Texas, where LBJ just happened to hail from, and back then the race to the moon project was explicitly hailed as a way to spend money in the South and increase its tech know-how.
      - msl 10y ago
        Could you elaborate a bit? What was "the crazy scheme of Apollo?"
        hga 10y ago
- mikeash 10y ago
  It had them in theory, but they were all too dangerous to actually test, so nobody is really sure if they would have worked.
mino 10y ago
Actually, Dragon's escape system might have worked in this case. See this gif made by someone on reddit: https://www.reddit.com/r/space/comments/50r7vx/crew_dragon_test_abort_speed_compared_to_falcon_9/ https://www.reddit.com/r/space/comments/50r7vx/crew_dragon_t...
- burger_moon 10y ago
  There's surprisingly a pretty good conversation surrounding it on there as well.

by hga 10y ago

sandworm101 10y ago

> Shuttle that was anomalous in having no provisions for crew survival if something happened Shuttle had launch abort modes. There was a dead zone during SRB burn, but the rest of the assent had planned abort modes for saving the crew. https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes https://en.wikipedia.org/wiki/Space_Shuttle_abort_modes

ceejayoz 10y ago
Planned, but the bailout method in particular was deemed pretty likely to wind up with a bunch of dead astronauts, as it required unbuckling and making your way to a hatch and jumping out at potentially several times the speed of sound from an out-of-control launch vehicle.
- kobeya 10y ago
  Not to mention emergency life support requiring active intervention to work. It was like having seat belts that required you to push a button to engage in the event of a crash. Not surprisingly not a single astronaut survived Columbia's depressurization at altitude, because of failure to engage active life support. (A blessing because they had a literal snowballs chance in hell of surviving what followed, but still...)
- sandworm101 10y ago
  Launch aborts are not an options for any tumbling vehicle. A launch abort from a spinning/tumbling rocket would see the capsule fired strait into the ground. Any out of control vehicle is pretty much a lost cause. Shuttle's abort modes, including the bailouts, were premised on the craft being under control. Given the forces involves, if it wasn't under control it probably was about to disintegrate. But the same is true of spaceX-style capsule launches. Whether parachutes would correct a tumbling capsule, or rip it in half, is an open question. They both need to initiate abort procedures at least a millisecond before the craft departs into uncontrolled flight. (And aborts can be triggered automatically, or by someone on the ground.)
  - XorNot 10y ago
    Launch abort though can be fired well in advance of a rocket tumbling though. There's a pretty narrow recoverable angle throughout the launch, the rocket is lost well before the crew can't be saved.
  - ceejayoz 10y ago
    Spinning's entirely possible to survive. The Saturn missions tested it (and it was a really good test - something went wrong and the rocket actually went out of control) - https://www.youtube.com/watch?v=AqeJzItldSQ https://www.youtube.com/watch?v=AqeJzItldSQ A tumble should be fairly trivial to detect and fire only when the capsule's in its upwards pointing portion of the tumble. Plus, you'd only be firing into the ground if you're pretty early in the launch - the Dragon launch abort only sent it up a kilometer or so. Finally, the launch abort is pretty sensitive - deviating not far off the right direction should trigger it, before a full-on tumble.
- Sir_Cmpwn 10y ago
  RTLS was also a death wish, turning the boat around at those speeds was likely to destroy it.
hga 10y ago
There was a dead zone during SRB burn Those alone made it a serious death trap, if you're designing man-rated systems, you like the big boosters to be liquid fueled because you can turn them off if needed, and in many if not most of the relevant failure modes they'll effectively do that anyway. And getting back to my point, as echoed by others, none of these equal a launch escape system, a "Get me the hell out of here!" system for when things have gone horribly and irretrievably wrong with the main system. Particularly unforgivable when it was billed as a boring space truck, when in reality it needlessly ran on the hairy edge in many of its systems. Add the post-Apollo NASA's public works attitude, and we ended up with NASA killing two shuttles and their crews.
- digi_owl 10y ago
  Best i recall, NASA wanted liquid boosters etc, but congress nixed it for pork barrel reasons.
  - hga 10y ago
    In an analysis published in Science that I read, the biggest driver was development cost. SRBs, in fact, the kludge of the big tank, were all done to minimize that, while drastically driving up operational costs, which, of course, were several elections down the road and sort of hidden/not entirely undesired for what had become almost entirely a public works program. By the same token, I heard first hand from the guy who developed the reentry vehicle that the crazy scheme of Apollo which left us with no operational hardware off the earth was done because it spent "a billion" (8 billion in 2016 dollars) more in Texas, where LBJ just happened to hail from, and back then the race to the moon project was explicitly hailed as a way to spend money in the South and increase its tech know-how.
    - msl 10y ago
      Could you elaborate a bit? What was "the crazy scheme of Apollo?"
      - hga 10y ago
mikeash 10y ago
It had them in theory, but they were all too dangerous to actually test, so nobody is really sure if they would have worked.

mino 10y ago

Actually, Dragon's escape system might have worked in this case. See this gif made by someone on reddit: https://www.reddit.com/r/space/comments/50r7vx/crew_dragon_test_abort_speed_compared_to_falcon_9/ https://www.reddit.com/r/space/comments/50r7vx/crew_dragon_t...

burger_moon 10y ago
There's surprisingly a pretty good conversation surrounding it on there as well.