Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site lsuc.UUCP 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