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Path: utzoo!lsuc!msb
From: msb@lsuc.UUCP (Mark Brader)
Newsgroups: net.space
Subject: Shuttle atmosphere - why just N2, O2?
Message-ID: <751@lsuc.UUCP>
Date: Mon, 12-Aug-85 18:35:35 EDT
Article-I.D.: lsuc.751
Posted: Mon Aug 12 18:35:35 1985
Date-Received: Mon, 12-Aug-85 18:58:40 EDT
References: <53@ssc-vax.UUCP> <1273@utcsri.UUCP> <534@leadsv.UUCP>
Reply-To: msb@lsuc.UUCP (Mark Brader)
Distribution: net
Organization: Law Society of Upper Canada, Toronto
Lines: 15
Summary: Isn't air cheaper?


Jerry Hollombe quotes  The Space Shuttle Operator's Manual:

> "An atmosphere like the earth's is  maintained  in  the  crew  compartment.
> Atmospheric  pressure  is  14.7  psi  ...  the  same  as standard sea-level
> conditions.  The atmosphere consists of 79% nitorgen and 21% oxygen,  again
> very  close  to what you left on earth.

So my question is why they use THIS atmosphere rather than plain air
(78% nitrogen, 21% oxygen, 1% argon).  I would imagine the oxygen supply
is in a different reservoir so that pure oxygen can be used if necessary,
but even so, the other reservoir could contain air-minus-oxygen rather
than straight nitrogen, and I would think that that is cheaper to produce.

Mark Brader