Path: utzoo!attcan!uunet!pyrdc!pyrnj!rutgers!mailrus!umich!cja
From: cja@zippy.eecs.umich.edu (Charles J. Antonelli)
Newsgroups: sci.space.shuttle
Subject: why is there air in the air packs?
Summary: why no oxygen in the air packs for emergencies at altitude?
Message-ID: <1177@zippy.eecs.umich.edu>
Date: 19 Sep 88 21:29:04 GMT
References: <14956@ames.arc.nasa.gov> <1988Sep17.073035.29265@utzoo.uucp>
Sender: news@zippy.eecs.umich.edu
Reply-To: cja@zippy.eecs.umich.edu (Charles J. Antonelli)
Organization: University of Michigan EECS Dept. Ann Arbor
Lines: 30
UUCP-Path: ihnp4!umich!eecs.umich.edu!cja

In article <1988Sep17.073035.29265@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>[discussion of challanger disaster forensic report deleted]
>One remaining uncertainty is whether the crew were conscious all the way
>down.  The key question is whether the cabin held pressure.  The emergency
>packs held *air*, not *oxygen*, and would not have prevented quick loss
>of consciousness at the breakup altitude.

i suppose that this point has been rehashed before, but i'll ask it anyway:
if the air packs cannot prevent loss of consciousness at the breakup altitude,
then what good are the air packs?  they could be used to provide breathable
air in the event of a cabin fire at low altitude, i suppose.  but why not
enrich the oxygen content so that the packs would work at high altitude
as well?

it might be that the designers assumed that any problems that occur at
extreme altitude severe enough to require emergencey breathing equipment
would probably be fatal anyway.  the challenger disaster certainly seems 
to have followed that model, and in this case the presumed loss of
consciousness on the part of the flight crew before impact was probably
a blessing.

it may also be that lots of oxygen canisters in the cabin constitute a
risk in themselves.

anybody in the know care to mail me an answer?

Charles J. Antonelli          Internet: cja@crim.eecs.umich.edu
44 ATL, 1101 Beal Ave.        Uucp: {uunet,rutgers}!umix!eecs.umich.edu!cja
The University of Michigan    Phone: 313-936-9362
Ann Arbor, MI   49109-2210    "When the going gets tough, the tough reboot."