Progress 21

Progress 21 (Прогресс 21) was a Soviet uncrewed Progress cargo spacecraft, which was launched in May 1984 to resupply the Salyut 7 space station.

Launch
Progress 21 launched on 7 May 1984 from the Baikonur Cosmodrome in the Kazakh SSR. It used a Soyuz-U rocket.

Docking
Progress 21 docked with the aft port of Salyut 7 on 10 May 1984 at 00:10 UTC, and was undocked on 26 May 1984 at 09:41 UTC.

Decay
It remained in orbit until 26 May 1984, when it was deorbited. The deorbit burn occurred at 15:00:30 UTC, with the mission ending at around 15:45 UTC.