Defunct Spy Satellite Falling From Orbit, page 4

reply to post by LwSiX

Depending on how you define the word issue, there have been plenty of issues with satellites and other space debris re-entering the Earth's atmosphere. According to Nuclear Space, a group which advocates for the use of nuclear power sources in spacecraft, a list of accidents/incidents involving re-entering radioactive material includes the following:

For the United States:

1) One DoD satellite powered by a SNAP (Space Nuclear Auxiliary Power)-9A plutonium RTG. The satellite failed to reach orbit on April 24, 1964, and resulted in the release of the plutonium into the atmosphere.

For the Soviet Union:

1) One 1969 COSMOS mission which failed to reach orbit. This incident resulted in the release of the RTGs radioactive material into Earth's atmosphere.

2) A second 1969 COSMOS mission which failed to properly initiate a burn which would have sent it into lunar orbit. Again, the RTGs in question burned up in the atmosphere and released radioactivity.

3) The launch failure of a 1973 RORSAT (Radar Ocean Reconnaissance SATellite) with an on-board nuclear reactor. This incident resulted in the release of radioactivity.

4) Another COSMOS mission - this one powered by a nuclear reactor - failed a burn which would have put it in a "nuclear safe-storage" orbit - that is, an orbit high enough that it would not decay for thousands of years. The satellite re-entered in 1978 and the reactor survived re-entry, crashing in Canada and releasing radioactivity. A joint recovery/cleanup operation was reportedly successful.

5) Another COSMOS mission - this one reportedly a RORSAT (the Soviets labeled pretty much anything a COSMOS mission) - with another nuclear reactor on board failed to reach a proper orbit in 1982 and re-entered the atmosphere in 1983. Again, radioactivity was released into the atmosphere.

So there we go. That's just incidents involving nuclear material, and then only the incidents that we know about. There could possibly have been others the public is currently unaware of - although any incident resulting in the release of respectable amounts of radiation into the atmosphere would be detectable by many people and organizations in many different countries, so there's little likelyhood such an incident could be covered up forever.

If we expand the scope of the discussion to include other hazardous but non-nuclear materials, the list grows too long to mention. Many satellites include maneuvering thrusters powered by hypergolic fuels, and these fuels are usually carcinogenic. Then there are spent upper stages of rockets - also possibly powered by hypergolics - satellites whose construction might include materials like mercury and lead...

Well, you get the idea. Other info is available from Space.com, and there are other resources out there. Google is your friend.