Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!bellcore!faline!thumper!karn
From: karn@thumper.bellcore.com (Phil R. Karn)
Newsgroups: sci.space.shuttle
Subject: Re: TDRS-C means never having to say LOS?
Summary: south atlantic anomaly
Message-ID: <1343@thumper.bellcore.com>
Date: 5 Oct 88 22:54:00 GMT
References: <6732@dasys1.UUCP> <1934@kalliope.rice.edu>
Organization: Bell Communications Research, Inc
Lines: 13

The South Atlantic Anomaly has absolutely nothing to do with TDRS
coverage. It is simply a region of the Van Allen belts that comes
somewhat closer to the earth's surface (i.e., down to low earth orbit)
due to the orientation of the earth's magnetic field.  Most of the
radiation encountered by low orbit spacecraft is in this region. (The
soft memory errors seen by the UoSAT-OSCAR spacecraft have largely been
in this region).

The gap in TDRS coverage is due to simple geometry: for both satellites
to be visible from White Sands at reasonable elevation angles, a region
near India had to be left uncovered.

Phil