Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Recovering HST from orbit
Message-ID: <1991Feb7.205749.16444@zoo.toronto.edu>
Organization: U of Toronto Zoology
References: <6814@harrier.ukc.ac.uk> <1614@mpirbn.mpifr-bonn.mpg.de>
Date: Thu, 7 Feb 1991 20:57:49 GMT

In article <1614@mpirbn.mpifr-bonn.mpg.de> p515dfi@mpirbn.UUCP (Daniel Fischer) writes:
>... (question to Henry at all: how much pollution does a Shuttle
>typically produce in its vicinity dyring an orbital rendezvous, like when
>they captured LDEF a year ago? Did they find traces of the thruster exhaust
>on the satellite?).

I hadn't heard of anything like that, although they were relatively careful
about thruster firings while in the immediate vicinity, as I recall.
Hydrazine/N2O4 thrusters are moderately "clean".  However, there has been
enough concern about such issues, especially for space stations and the
like, that at least one reusable-manned-spacecraft proposal I've seen had
a small set of compressed-nitrogen thrusters for maneuvering in areas
where normal rocket exhausts would be undesirable.
-- 
"Maybe we should tell the truth?"      | Henry Spencer at U of Toronto Zoology
"Surely we aren't that desperate yet." |  henry@zoo.toronto.edu   utzoo!henry