
How NASA engineered the Chilean miners' escape pod - jaxonrice
http://www.aolnews.com/world/article/nasa-engineer-clinton-cragg-thought-small-to-design-rescue-capsule-for-chilean-miners/19667140
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robchez
I helped design the drill (raisebore) used to get to the miners. It was by
pure chance the rig was in the country at the time this happened.

Today is one of those "I did something that matters" moments for me.

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marvin
Could you give some details about how and why you got this job, and what
considerations had to be made when designing it?

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robchez
What they use these machines for normally is to drill shafts for ventilation
or egress in mines. Generally there are two ways to drill shafts, top down
(blind sinking etc.) or bottom up (raiseboring). Top down shafts used to be
predominate, but these days they are only used for larger shaft diameters
5.5m+.

What you do is drill a pilot hole down for the shaft, attach the reamer head,
then literally pull the drill rig upwards to ream the hole. Obviously in this
case we can't get the reamer down there so they are using the pilot shaft hole
to get the guys out (hence the tiny capsule!)

The rig (Strata 950) is used all over the world for these jobs, and it wasn't
specifically designed for this, it just happened to be there at the time.

The major design considerations were the massive forces and torques that would
be applied. However the biggest worry we had was the impact and fatigue
strength of the rig, especially the reamer. This thing has upwards of 500T of
thrust pulling it up and 600kNm of Torque on a 5.5m head. If it encounters a
void or some other ground anomaly and it stalls or hits something, the damage
it can cause is massive. It has been a while but I remember 25mm welds
throughout it.

Hope that wasn't too long winded, but it is as 'simple' as I could really make
it during my lunch break.

edit: some clarification

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rdoherty
To me, this sounds like the "old NASA" that I read and heard about from the
60's. Limited time frame, small team and a focused goal. Is there a way we can
get NASA back to that type of organization?

If we did that (and had some audacious goals), I think it would get the public
interested in space travel again.

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bluesnowmonkey
Maybe this perception exists because there is less for NASA to do. There's not
a lot for astronauts to do in space until we have some kind of breakthrough in
propulsion. It's too slow and expensive to get around the solar system until
then.

So for now we put up satellites and telescopes, send out probes, help with the
ISS, and... study the sky. These jobs get done with what we have now. What
great mission would even require the kind of NASA that existed in the 60s?
Please don't say Mars.

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waterlesscloud
Why not say Mars?

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krakensden
There's no point, other than flag planting.

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skeletonjelly
I can only imagine what it would be like to be inside a drill hole compressed
inside a capsule and surrounded by rock for 20 minutes with the possibility of
it being jammed. I can't help but to drag a comparison between surfacing out
of this cramped chamber and birth. Instead of only the mother I'm sure the
miners and their families will be under the effects of an endorphin rush.

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jacquesm
That puts the term 'mother earth' in a completely new perspective.

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ryanwaggoner
It would be pretty nerve-wracking to be the last one to go up.

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kingofspain
According to the BBC just now, the miners are trying to decide who will have
the honour of being last out.

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sledmonkey
And the record for the longest time spent underground.

