The Soviet nuclear-powered satellite Kosmos 954 burned up during atmospheric reentry, scattering radioactive debris across Canada's Northwest Territories.

Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as Voyager 2. Reactors producing controlled fusion power have been operated since 1958 but have yet to generate net power and are not expected to be commercially available in the near future.

Kosmos 954 was a reconnaissance satellite launched by the Soviet Union in 1977. A malfunction prevented safe separation of its onboard nuclear reactor; when the satellite reentered the Earth's atmosphere the following year, it scattered radioactive debris over northern Canada, some of the debris landing in the Great Slave Lake next to Fort Resolution, Northwest Territories.

Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. Atmospheric entry may be uncontrolled entry, as in the entry of astronomical objects, space debris, or bolides. It may be controlled entry of a spacecraft that can be navigated or follow a predetermined course. Methods for controlled atmospheric entry, descent, and landing of spacecraft are collectively termed as EDL.

The Northwest Territories is a federal territory of Canada. At a land area of approximately 1,127,711.92 km² (435,412.01 sq mi) and a 2021 census population of 41,070, it is the second-largest and the most populous of the three territories in Northern Canada. Its estimated population as of the first quarter of 2025 is 45,242. Yellowknife is the capital, most populous community, and the only city in the territory; its population was 20,340 as of the 2021 census. It became the territorial capital in 1967, following recommendations by the Carrothers Commission.