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Path: utzoo!watmath!clyde!burl!ulysses!gamma!epsilon!zeta!sabre!petrus!karn
From: karn@petrus.UUCP (Phil R. Karn)
Newsgroups: net.space
Subject: Re: Re: Debris from Upcomming ASAT Test
Message-ID: <620@petrus.UUCP>
Date: Thu, 3-Oct-85 03:05:54 EDT
Article-I.D.: petrus.620
Posted: Thu Oct  3 03:05:54 1985
Date-Received: Fri, 4-Oct-85 05:36:43 EDT
References: <385@aurora.UUCP> <15800003@uiucdcsp> <108@muscat.UUCP> <634@osu-eddie.UUCP>
Organization: Bell Communications Research, Inc
Lines: 47

> Another case of OK for us, not OK for them? The USA uses nuclear power
> plants. Take a look at the Voyager and Pioneer spacecraft.  But those
> are deep space vehicles! you say?  Until they get into deep space they
> can still fall.  That's even more of a problem in these days of shuttle
> launch rather than booster launch.

Very true. The US has flown plenty of plutonium-239-fueled thermisotope
generators, since they are the only practical power sources for deep space
probes like Pioneer and Voyager (not enough sunlight) or probes designed to
operate continuously on the surfaces of other planets (Apollo ALSEP,
Viking).  However, to date we have actually flown only one nuclear reactor
in orbit. I believe this was on a Transit navigational satellite in the
middle 60's.

The American space program has had its nuclear mishaps too. Remember Apollo
13? There is a few kg of plutonium sitting on the bottom of the Pacific
Ocean somewhere if you want to get it. It was the fuel source for the ALSEP
package which came back when the lunar module "lifeboat" burned up during
re-entry.

The real difference, however, between the American and Soviet uses of
nuclear power in space is not just that the Soviets fly many more of them
than we do.  It's that they're incredibly irresponsible in their designs.
Their nuclear-powered ocean survellance radar satellites operate in very low
earth orbits.  When such a satellite wears out, normal procedure is to boost
it up to a long-lived orbit; however, if that move fails it is bound to
re-enter within a few weeks or months, and that's exactly what happened with
Cosmos 954 and 1402. This is much worse than having a launch failure for two
reasons:

1. "Unburnt" plutonium or uranium is only weakly radioactive, and its alpha
emissions are easily shielded (the Apollo astronauts handled the plutonium
sources for ALSEP with their gloved hands). However, a reactor that has been
running for a while becomes extremely hot because of accumulated fission
products.

2. Re-entry could occur almost anywhere, instead of over the ocean or
Siberia as would be the case with most launch failures.

I wonder if the Americans have considered this point. It was mentioned in
the Scientific American article that these ocean surveillance satellites are
the ones that the Pentagon worries about the most. It just occurred to me
that shooting one of these down with our ASAT would guarantee that its
radioactive remains re-enter the atmosphere within a pretty short time. A
real game of Russian Roulette.

Phil


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