Kosmos 954 was a reconnaissance satellite launched by the Soviet Union in 1977, powered by a nuclear reactor containing 50Kg of highly enriched uranium-235
Soviet officials … lost control over the vehicle, and the system which was intended to propel the spent reactor core into a safe disposal orbit … failed.
When the satellite reentered the Earth's atmosphere the following year, it scattered radioactive debris over northern Canada. The Canadian government billed the Soviet Union for over $6 million under the terms of the Outer Space Treaty (which obligates states for damages caused by their space objects). The USSR eventually paid 3 million Canadian dollars in compensation.[4] https://en.wikipedia.org/wiki/Kosmos_954
There are currently 32 nuclear reactors in LEO: one SNAP-10A, two Topaz and 29Bouk. https://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=2005ESASP.587..551J&db_key=AST&page_ind=1&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
When the next LEO reactor de-orbits, will it have the capacity to enter a planned “safe disposal trajectory”, or will it be an uncontrolled derelict?
