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Comment by ejr | Hacker News Reader

The shuttle had its own variant although that was manual, not automatic http://www.popularmechanics.com/science/space/nasa/4262479

I believe it doesn't matter what the craft is, there is always some manner of self-destruct to ensure a larger population isn't threatened by debris from an exploding rocket.

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It does matter. I doubt you'll load 300 willing passengers on a 747 if it was widely known it had a self destruct.

I would guess each case has to weigh its pros and cons for inclusion of a system. There is such thing as acceptable risk to population. If FAA mandated them carte blanche, Michael Bay movies would become documentaries.

A 747 isn't a spacecraft travelling at supersonic speeds, so it's not really the type of craft relevant to the discussion. Cars, buses and boats also aren't loaded with self-destruct mechanisms for obvious reasons.

Obvious enough that I had assumed craft = aircraft as well since you can "take the keys out" of ground/water vehicles. I was challenging the thought that every aircraft needs self destruct, as I suspect it's a minority. If as you say supersonic capability is the threat threshold, fighter jets/rockets would have them but a C-5 Galaxy and Blackhawk might not (I don't know, I'm speculating).

In this context, I meant craft = spacecraft. Our current space launch technology relies on extremely volatile and dangerous fuel. Until that changes, a self destruct will be found in all large launch vehicles[1]

https://en.wikipedia.org/wiki/Launch_vehicle

The threshold is more "Is it an unstable flying fuel tank* ? y/n"

*or solid block of fuel

I guess, military personnel (that astronauts so far have basically been) are less skittish in that regard than civilians.

Especially since it is understood that space travel is dangerous, while air travel is regarded as safe.

According to Neil Armstrong, Apollo 11 only had a "50–50 chance" of landing safely on the Moon's surface. They're willing to take enormous risks.

That might be out of context. There were a whole lot of points where the mission could have been safely aborted had any parameter been unacceptable. Look at Apollo 10, which was identical to 11 except for turning around when the lander was a few km above the surface. Failure to land does not mean a risk to safely. The risk wasn't survival, it was failing to complete the primary mission objective.

You might be right. Apparently, he thought they had a 90% chance of getting back safely to Earth.

It's one of the things you have to take into account for being one of only twelve human beings to walk on the surface of the moon.

I'd love to think that I would be able to do it, and whenever I get the slightest skittish on a plane, I laugh that I don't think I would hack it.

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