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From: rjnoe@riccb.UUCP (Roger J. Noe)
Newsgroups: net.space
Subject: Re: communications satellite insurance rates
Message-ID: <530@riccb.UUCP>
Date: Tue, 17-Sep-85 09:25:36 EDT
Article-I.D.: riccb.530
Posted: Tue Sep 17 09:25:36 1985
Date-Received: Wed, 18-Sep-85 05:14:51 EDT
References: <536@petrus.UUCP> <528@riccb.UUCP> <539@petrus.UUCP>
Organization: Rockwell International - Downers Grove, IL
Lines: 73

> . . . Westar-6 and Palapa-B had PAM failures, and
> PAMs are unnecessary with Ariane because the latter puts you directly in a
> 35800 x 200 km geostationary transfer orbit. Only one additional burn
> is needed to reach a circular geostationary orbit.

Right, but the vast majority of failures to get satellites on station are
due to a problem while the payload is still within the launcher.

> What's important when it comes to insurance rates is the overall probability
> of the spacecraft reaching its proper orbit and actually doing its job. It
> doesn't matter whether the satellite goes down in the Atlantic, gets stuck
> in a useless LEO, or arrives at GEO only to die (like the recently launched
> Syncom).

Quite correct.  But as I pointed out, both historical evidence and recent
experience demonstrates that most things go wrong before the launcher has
released its payload.

> When it works, Ariane is a much "friendlier" launcher for communications
> satellites than the Shuttle.

The advantages you note for ELVs in general and Ariane in particular are
granted.  But the operative phrase here is "when it works."

> . . . you can use a smaller apogee kick
> motor, allowing increased payload weight.

Only to a limit.  There are a lot of satellites that simply cannot be lifted
(to GEO transfer orbit) by Ariane, Delta, Atlas, or even Titan because of
their maximum capacity.  But since you were probably intending this to apply
strictly to communications satellites (of which the HS-376 type is typical)
this point is moot.

> . . . Ariane deploys you immediately
> after reaching orbit; the Shuttle holds onto you for a day or two during
> which time you have no solar power, attitude control or control over the
> thermal environment.

You don't need it when you're safely tucked away in the womb of the shuttle
cargo bay.  Ariane can do no such thing because it does not provide as
"friendly" an environment as the shuttle does.

> It has been sheer luck that there have been three opportunities for in-space
> salvage or repair of satellites launched on the shuttle whose upper stage
> engines failed.

You're right - it was sheer BAD luck for the shuttle that these "oppor-
tunities" occurred.  People tend to blame NASA and the shuttle even when one
of its contractors, customers, or the military screws up one of the motors
for which NASA has no responsibility or control.  Many saw the initial
failure of Westar VI and Palapa B-2 as a shuttle problem.  Of course, SMM
(Solar Maximum Mission) was a complete success since it was not deployed
by the shuttle.  There are going to be a LOT of similar events in coming
years involving retrieval, repair and/or refueling of satellites in LEO.

> . . . Once the satellite leaves the rather narrow set of orbits
> that are accessible to the Shuttle, it's on its own.  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.
> 
> Phil

All of which is true of expendable launchers as well as the shuttle.  No
difference at all.  So what's your opinion, Phil (and anyone else), do you
think the latest Ariane failure will affect insurance rates and how?  Will
this apply just to Ariane or to all expendable launchers?  How will it
affect the insurance rates of satellites launched by the shuttle?

What really gets me is that ESA gets to keep all its fee for blowing up its
payload.  That's something NASA would never do with the shuttle.
--
Roger Noe			ihnp4!riccb!rjnoe