Re: radioactive debris
Leo Barhorst (leobarhorst@pi.net)
Mon, 22 Jan 96 20:33:15 PST
As mentioned in an earlier message I would go through the articles in
Space News listed in that message.
Most of the articles had to do with the status of the nuclear space
propulsion projects in the US and the purchase by the US of four
additional Topaz reactors from Russia; purely for testing. The tone
of the articles is that nuclear space propulsion has almost ceased to
exist in the US. The only program at the moment is the manufacturing
of the RTG's for the Cassini spacecraft to Saturn, due for launch in 1997.
Much more interesting is the article in SN Feb 13-19, 1995: Russian Satel-
lites suspected as space debris source.
The Lincoln Laboratory's Haystack radar system near Boston supported a
NASA research in charaterizing the size of space debris. They detected that
the Cosmos 1900 spacecraft, is leaking coolant (sodium potassium) from its
nuclear power source. Cosmos 1900, a Radar Ocean Reconnaissance Satellite
using a nuclear reactor to power its surveillance equipment, was launched
in december 1987, but suffered a boost problem that left it in a lower than
planned orbit. One year later the satellite was turned off and transferred
to a higher orbit.
The Haystack radar detected that the leaking coolant is streaking through
space in the form of tiny spheres at an altitude of between 900 and 1000
kilometers. It is not know whether the coolant is radioactive or not, ac-
cording to Nicholas Johnson. There may be slight residual radioactivity.
As many as 30 of the nuclearpowered radar satellites have been orbited
since the late 1960's, each with a large resevoir of the coolant. The
leaks could be caused by hits from meteorites, space debris hits or
corrosion. The coolant, in the range of 70.000 droplets dominates the
environment at the altitude they orbit.
After the 1978 crash of the nuclearpowered Cosmos 954 in Canada the
Russians have redisgned their reactor-carrying spacecraft to eject the
radioactive fuel core into higher orbits when the spacecraft were retired.
Left behind in low orbit is the main body of the spacecraft and its
coolant supply. Johnson thinks it is conceivable that the redisign had
led to the leakage, as plumbing connections holding the coolant may not
seal properly after the core is ejected.
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Name: Leo Barhorst
E-mail: leobarhorst@pi.net
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