Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!rutgers!att!cbnewsl!sw
From: sw@cbnewsl.ATT.COM (Stuart Warmink)
Newsgroups: sci.space.shuttle
Subject: Re: Shuttle-ground communication
Summary: TDRS <-> TDRS ?
Message-ID: <354@cbnewsl.ATT.COM>
Date: 29 Mar 89 18:22:52 GMT
References: <1194@ncrcce.StPaul.NCR.COM> <1443@cfa237.cfa250.harvard.edu> <11563@ut-emx.UUCP>
Organization: Interface Systems at AT&T Bell Laboratories
Lines: 18

In article <11563@ut-emx.UUCP>, tca@ut-emx.UUCP (Tobin C. Anthony) writes:
> [..............] NASA only wants to have one TDRS ground station and they
> want to keep it at White Sands.  Both TDRS spacecraft can see White Sands
> from their positions.  Having a third TDRS would require an additional
> ground station on the opposite side of the Earth from White Sands. [...]

In theory, the 3rd TDRS could communicate with White Sands via one of the
other two TDRSs. In practice, as Tobin said, 85% coverage is good enough,
especially considering the extra cost of launching and maintaining an 
additional TDRS.

By the way, does anyone know if TDRS-D has reached its operational position
yet, or is it still being checked-out?
-- 
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