Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: LM pressurization question
Date: Tue, 27 Jun 2000 22:34:08 GMT

In article <394F4720.EEC88CA2@bigpond.net.au>,
David Sander  <surfren@bigpond.net.au> wrote:
>...The ITMG was designed to be partly removable...
>...but certainly not to the extent where you
>could patch up a hole made on anywhere away from the edges. Besides, the
>likeliest source of a hole is a meteoroid, and if one of those hit you, a
>suit breach is the least of your worries.

Actually, it has been suggested that a *small* micrometeoroid penetration
might well result in nothing more than local injury and burns, plus a
persistent air leak.  That is, it would be survivable if the air holds out
or the leak can be sealed.

The one possible gotcha in that is the possibility that the inner layers
of the suit might ignite.  This is difficult to determine, because the
high-velocity-impact test rigs tend to involve things like hydrogen gas
guns, which for safety reasons cannot test *oxygen-filled* suits.  It's a
little ominous that the impact hole itself tends to have charred edges.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.history
From: henry@spsystems.net (Henry Spencer)
Subject: Re: LM pressurization question
Date: Wed, 28 Jun 2000 13:57:35 GMT

In article <39596A2C.201B7D48@bigpond.net.au>,
David Sander  <surfren@bigpond.net.au> wrote:
>> Actually, it has been suggested that a *small* micrometeoroid penetration
>> might well result in nothing more than local injury and burns...
>> The one possible gotcha in that is the possibility that the inner layers
>> of the suit might ignite...
>
>Other than the scorching and searing of human flesh, any ignition would have
>been extinguished fairly rapidly, I would imagine...
>The inner layers of the PGA were themselves not prone to burn per se...

No, but with the exception of the beta cloth, they *are* at least
technically flammable.  Remember, it's an oxygen-rich environment with
high flow velocities; the vulnerability to sustained fire in those
conditions is poorly understood.  As of a few years ago (the paper I saw
was dated 1996), there was thought to be some possibility that a localized
fire might develop in the event of such a puncture.  The big concern was
that it might enlarge the hole.
--
Microsoft shouldn't be broken up.       |  Henry Spencer   henry@spsystems.net
It should be shut down.  -- Phil Agre   |      (aka henry@zoo.toronto.edu)