Kosmos 954 - Launch and Operation

Launch and Operation

The satellite was part of the Soviet Union's RORSAT programme, a series of reconnaissance satellites which observed ocean traffic, including surface vessels and nuclear submarines, using active radar. It was assigned the Kosmos number 954 and was launched on September 18, 1977 at 13:55 UTC from the Baikonur Cosmodrome, on a Tsyklon-2 carrier rocket. With an orbital inclination of 65°, a periapsis of 259 kilometres (161 mi) and apoapsis of 277 kilometres (172 mi), it orbited the Earth every 89.5 minutes. Powered by a liquid sodium-potassium thermionic converter driven by a nuclear reactor containing around 110 pounds (50 kg) of Uranium 235, the satellite was intended for long-term on-orbit observation, but by December 1977 the satellite had deviated from its designed orbit and its flightpath was becoming increasingly erratic. In mid-December North American Aerospace Defense Command, which had assigned the satellite the Satellite Catalog Number 10361, noticed Kosmos 954 making erratic manoeuvres, changing the altitude of its orbit by up to 50 miles, as its Soviet operators struggled to control their failing spacecraft. In secret meetings Soviet officials warned their US counterparts that they had lost control over the vehicle, and that the system which was intended to propel the spent reactor core into a safe disposal orbit had failed.

At 11:53 AM GMT on January 24, 1978 Kosmos 954 reentered the Earth's atmosphere while travelling on a northeastward track over western Canada. At first the USSR claimed that the satellite had been completely destroyed during re-entry, but later searches showed debris from the satellite had been deposited on Canadian territory, including portions of the Northwest Territories (some of which is now Nunavut), Alberta and Saskatchewan, along a 600-kilometre (370 mi) path from Great Slave Lake to Baker Lake.