Sputnik 22

Sputnik 22 was an attempted Mars flyby mission, presumably similar to the Mars 1 mission launched 8 days later. The intended Mars probe had a mass of 893.5 kg. The spacecraft and attached upper stage, with a total mass of 6500 kg, were launched by an SL-6 into a 180 x 485 km Earth parking orbit with an inclination of 64.9 degrees and either broke up as they were going into Earth orbit or had the upper stage explode in orbit during the burn to put the spacecraft into Mars trajectory. In either case, the spacecraft broke into many pieces, some of which apparently remained in Earth orbit for a few days.

This occurred during the Cuban missile crisis and the debris was detected by the U.S. Ballistic Missile Early Warning System radar in Alaska and was for a while feared to be the start of a Soviet nuclear ICBM attack.