(4 of 4)
One of the Soviet predecessors of 954 broke up on re-entering the atmosphere in 1973 and fell into the Pacific north of Japan. Two Russian moon-bound craft, which used radioactive fuels to heat their capsules, went into earth orbit in 1969, but dropped back into the atmosphere and burned out with some release of detected high-altitude radiation.
The U.S., which has been using SNAP (Systems for Nuclear Auxiliary Power) power packs since 1961, has had three accidents. A Navy navigation satellite failed to reach orbit in 1964 and disintegrated in the atmosphere over Madagascar. A meteorological satellite was aborted on launch from Vandenberg Air Force Base in 1968, and the nuclear package was recovered intact. As Apollo 13 returned from an unsuccessful moon flight in 1970, the three astronauts had to jettison their unused moon lander, and its power pack plunged into the Pacific Ocean near Australia.
If the harm to man so far seems negligible, the very fact that such nuclear space accidents occur is chilling. For all the talk of "fail-safe" systems, as man hurls more and more lethal nuclear power plants into space, the probability increases of further, and much more harmful, "space age difficulties." -