Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!wuarchive!udel!rochester!dietz
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.space.shuttle
Subject: Re: Recovering HST from orbit
Message-ID: <1991Feb8.133106.15736@cs.rochester.edu>
Date: 8 Feb 91 13:31:06 GMT
References: <6814@harrier.ukc.ac.uk> <1614@mpirbn.mpifr-bonn.mpg.de> <1991Feb7.205749.16444@zoo.toronto.edu> <1991Feb8.075406.5464@cs.mcgill.ca>
Reply-To: dietz@cs.rochester.edu (Paul Dietz)
Organization: University of Rochester Computer Science Dept
Lines: 14

In article <1991Feb8.075406.5464@cs.mcgill.ca> sparky@cs.mcgill.ca (James R. SMITH) writes:

>Concern has been expressed about dirt and contamination in the payload
>bay during reentry with the HST.  Aren't we going to replace the mirror
>and support components once it's down here anyway?

It's never going to BE down here again.  Maintenance will be on orbit.
You can't replace the main mirror on orbit.

One particular concern with HST, I understand, is that the UV reflectivity
of the mirror is very sensitive to the presence of contaminants.

	Paul F. Dietz
	dietz@cs.rochester.edu