Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!cmcl2!phri!dasys1!tneff
From: tneff@dasys1.UUCP (Tom Neff)
Newsgroups: sci.space.shuttle
Subject: TDRS-C means never having to say LOS?
Summary: will air-to-ground be continuous as of STS-27?
Message-ID: <6732@dasys1.UUCP>
Date: 29 Sep 88 22:32:39 GMT
Reply-To: tneff@dasys1.UUCP (Tom Neff)
Organization: Independent Users Guild
Lines: 18

I know the TDRS network is supposed to provide continuous communication
with a lot of non-GEO satellites, and I also know that we get partial
air-to-ground coverage on Shuttle flights right now from the one TDRS
successfully deployed before STS-26.  As I write this, it appears Discovery
is deploying TDRS-C nominally.  Assuming the IUS works and the second
TDRS is parked and activated, will we henceforth have continuous downlink
during Shuttle missions from now on?  Or will the "LOS Guam, AOS Hawaii
in 6" game continue until we have three birds up there?

Second question - the early diagrams had an equilateral triangle of
TDRS coverage taking care of satellite and spacecraft comm.  But lately
I hear that when TDRS-D is deployed, TDRS-A will be parked as a hot
spare while C or D assumes its duties.  Are we still aiming for three
live birds at some point, or are we resigned to antipodal coverage?
-- 
Tom Neff			UUCP: ...!cmcl2!phri!dasys1!tneff
	"None of your toys	CIS: 76556,2536	       MCI: TNEFF
	 will function..."	GEnie: TOMNEFF	       BIX: t.neff (no kidding)