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That is my thinking too. The launch abort system can get the capsule away faster than the rocket blows up from a leak catching on fire. Several people have over

That is my thinking too. The launch abort system can get the capsule away faster than the rocket blows up from a leak catching on fire. Several people have overlaid the launch abort test video with the one that caught fire on the launch pad to roughly confirm this. This is more of the current culture of being so risk adverse that you end up with more risky behavior with the ‘mitigation’ than the original risk.

eesmith 8y ago
What's the failure rate of the abort system? What's the failure rate during fuel loading? That is, if we assume 0% failure rate of the abort system then your scenario works. If we assume (for argument's sake) a 50% failure rate in the abort system, and a 10% chance during fueling, then there's a 5% failure leading to human deaths. Without those numbers, it's hard to draw a conclusion.
- mikeash 8y ago
  That’s a good point. I suspect the abort system is much less likely to kill you, since it’s fairly simple, but it would be good to actually quantify that.
- greglindahl 8y ago
  The observed failure rate during fuel loading is 2% with a big error bar, based on one accident. And the cause of that accident has been mitigated. The expected failure rate for the LAS is pretty high, high enough that the loss of crew/mission statistic computation doesn't include the LAS.
  - mikeash 8y ago
    A bit of a nitpick: the observed failure rate is quite a bit lower. Each launch involves at least two fuelings, since they do a static fire before every launch (which is when the accident occurred). Every booster also gets tested at their facility in Texas, and there have been a lot of scrubs after fueling, so the average number of fuelings per launch is probably 3 or so. That’s around 150 total fueling events for the Falcon 9, or around 100 if you only count the ones with densifier propellants, making the failure rate so far around 0.6-1%.

eesmith 8y ago

What's the failure rate of the abort system? What's the failure rate during fuel loading? That is, if we assume 0% failure rate of the abort system then your scenario works. If we assume (for argument's sake) a 50% failure rate in the abort system, and a 10% chance during fueling, then there's a 5% failure leading to human deaths. Without those numbers, it's hard to draw a conclusion.

mikeash 8y ago
That’s a good point. I suspect the abort system is much less likely to kill you, since it’s fairly simple, but it would be good to actually quantify that.
greglindahl 8y ago
The observed failure rate during fuel loading is 2% with a big error bar, based on one accident. And the cause of that accident has been mitigated. The expected failure rate for the LAS is pretty high, high enough that the loss of crew/mission statistic computation doesn't include the LAS.
- mikeash 8y ago
  A bit of a nitpick: the observed failure rate is quite a bit lower. Each launch involves at least two fuelings, since they do a static fire before every launch (which is when the accident occurred). Every booster also gets tested at their facility in Texas, and there have been a lot of scrubs after fueling, so the average number of fuelings per launch is probably 3 or so. That’s around 150 total fueling events for the Falcon 9, or around 100 if you only count the ones with densifier propellants, making the failure rate so far around 0.6-1%.