Kosmos 1275

Kosmos 1275 was a part of a 6-satellite Soviet military navigation system, called the Parus series, distributed in orbital planes spaced 30 degrees apart, and launched from the Plesetsk cosmodrome aboard a Cosmos rocket. It is believed to be the first satellite destroyed by untracked Satellite debris. On 4th July 2025, Metop-B had to perform a collision avoidance manoeuvre to avoid Kosmos 1275 debris demonstrating the long term problem of spacecraft debris above an altitude of 600 km.
Kosmos 1275 was launched from the Plesetsk Cosmodrome in the Russian SSR on 4 June 1981. On July 24, 1981, at 23.51 GMT, it suddenly ceased operations and broke into more 300 large pieces of debris and many other too small to track. Because it had no propellant on board, it was believed that there was nothing internal that could have led to its break-up. However, it is possible that a battery explosion caused the breakup.