---- 11.4 Do reentering satellites ever spread radioactive material?

Unfortunately, yes. There are some 60 known spacecraft carrying nuclear power sources launched by the United States and the former Soviet Union. Much of the debris from Cosmos
954, mentioned above, was radioactive material. The Galileo spacecraft carried aboard the Space Shuttle in 1989 carries an RTG (Radioisotope Thermoelectric Generator). It successfully
achieved solar orbit and went on to Jupiter. A nuclear- powered navigation satellite launched by the USA in 1964 was not so lucky and failed to achieve orbit and is thought to have broken up and spread its radioactive materials into the atmosphere. In 1983, Cosmos 1402, carrying a nuclear reactor (RTG) disintegrated in the upper atmosphere over the South Atlantic Ocean and probably spread radioactive debris into the atmosphere.