Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!njin!princeton!udel!rochester!dietz
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.space.shuttle
Subject: Re: Hydrazine (EVA exposure)
Keywords: toxic, spacesuits
Message-ID: <1990Nov13.174130.4233@cs.rochester.edu>
Date: 13 Nov 90 17:41:30 GMT
References: <kNuDs2w163w@ehpcb.WLK.COM> <1990Nov13.142644.27781@eagle.lerc.nasa.gov>
Reply-To: dietz@cs.rochester.edu (Paul Dietz)
Distribution: usa
Organization: University of Rochester Computer Science Dept
Lines: 13

In article <1990Nov13.142644.27781@eagle.lerc.nasa.gov> spgreg@earth.lerc.nasa.gov writes:

>and EVA equipment can evaporate or sublime.  The astronaut is endangered 
>when he unseals his suit.  It is a real and serious concern and not just 
>when satellites in the vicinity use hydrazine--the shuttle itself does.  

More accurately, the shuttle uses monomethylhydrazine.  MMH is more
toxic than hydrazine when inhaled.  MMH is used because its melting
point, 220.7 K, is lower than that of hydrazine, 274.5 K, and because
it has better shock resistance and heat-transfer properties.

	Paul F. Dietz
	dietz@cs.rochester.edu