Re: Cosmos 2347 self-destruction

Phillip Clark (psclark@dircon.co.uk)
Sun, 12 Dec 1999 09:29:26 +0000 (GMT)

On Sat, 11 Dec 1999, Daniel Deak wrote:
> According to AviationWeek & Space Technology, the Russian ocean
> surveillance satellite, Cosmos 2347, was commanded to self-destruct
> in orbit on Nov. 22. The explosion left more than 130 pieces of debris
> in a 230 x 410 km orbit inclined 65 degrees.

This part of the Av Week story is monumental garbage.

The Russians have not revealed why these EORSATs disintegrate in orbit,
but the problem is most likely propulsion-related.   When the satellites
started to fly they would usually disintegrate in orbit and the best
theory is that it related to residual propellant in the spacecraft's
tanks.   After some time in orbit the residual propellant develops enough
pressure to cause a partial disintegration of the satellite.   There is
nothing intentional about the disintegrations.

In the mid-1980s the Russians started to reduce the perigee of the
satellites at the end of operations, thus ensuring that the satellites
would re-enter the atmosphere before the propellant pressure caused a
debris event.   In the last few years two satellites have remained
operational for so long that they suffered disintegration after having
their orbits lowered but before re-entry took place.

The re-entry of Cosmos 2347 marks the demise of the EORSAT programme: the
two-stage Tsyklon-M launch facilities at Baikonur were closed down around
a year ago and the launch team was disbanded.   One wonders how many
three-stage Tsyklons are still available for launch from Plesetsk: I did
hear that there were only around six available a couple of years ago.

Phillip Clark

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Phillip S Clark                                     22 Winterbourne Close
Molniya Space Consultancy                           Hastings
Compiler/Publisher, Worldwide Satellite Launches    E Sussex  TN34 1XG
                                                    U.K.

Specialist in "space archeology" - the older and more obscure the more 
interesting it is !
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