Although most falling debris is burnt up when it re-enters the atmosphere, there have been costly and potentially dangerous exceptions. On January 24, 1978, a nuclear-powered satellite launched by the erstwhile Soviet Union, Cosmos 954, crashed over northwestern Canada, spilling radioactive debris. The Canadian government presented the USSR with a bill of US $6 million for clean-up operations. After much wrangling, the USSR paid half the amount.

Later that year, two French farmers narrowly missed being flattened by a 20 kg lump of a Russian rocket re-entering the atmosphere, which landed in a potato field. And in July 1979, pieces of the 75-tonne US space station Skylab fell to earth. But the most curious