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Posting-Version: version B 2.10.2 9/18/84; site watdcsu.UUCP
Path: utzoo!watmath!watnot!watdcsu!broehl
From: broehl@watdcsu.UUCP (Bernie Roehl)
Newsgroups: net.space
Subject: Re: Re: Ariane destroyed
Message-ID: <1680@watdcsu.UUCP>
Date: Wed, 18-Sep-85 09:51:44 EDT
Article-I.D.: watdcsu.1680
Posted: Wed Sep 18 09:51:44 1985
Date-Received: Thu, 19-Sep-85 04:45:42 EDT
References: <536@petrus.UUCP> <528@riccb.UUCP> <539@petrus.UUCP>
Reply-To: broehl@watdcsu.UUCP (Bernie Roehl)
Organization: U of Waterloo, Ontario
Lines: 25

In article <539@petrus.UUCP> karn@petrus.UUCP (Phil R. Karn) writes:
>
>... If it had been the
>apogee kick motors that failed on Westar, Palapa or Syncom, there would have
>been no chance for in-orbit repair, just as there is no chance of an
>in-orbit repair on the one that was just launched.
>

True.  Of course, the same is true for the Ariane.  Indeed, with the Ariane
there is no chance at all of in-orbit repair, period.

A mission can fail at any of several points.  It can fail before LEO; this
has *never* happened with the Shuttle, but has happened several times with
the Ariane.  It can fail before injection into the transfer orbit; in this
case, the Shuttle can be used to make repairs and/or salvage the satellite
for subsequent re-launch.  With the Ariane, this kind of failure makes the
mission a write-off.  It can fail after injection; in this case, it may be
a failure in the transfer stage, or with the apogee kick motor.  If it's
the apogee kick motor, it could happen just as easily with an Ariane launch
as with a Shuttle launch (since it's the *satellite* manufacturer who provides
that stage).  The only failures thus far in Shuttle-launched satellites have
been in the trasfer stages, and in at least some of those cases it's been
possible to recover from the failure.

I'll put my money on the Shuttle, thanks.