Progress 7

Progress 7 (Прогресс 7) was a Soviet unmanned Progress cargo spacecraft, which was launched in June 1979 to resupply the Salyut 6 space station.

Spacecraft
Progress 7 was a Progress 7K-TG spacecraft. The seventh of forty three to be launched, it had the serial number 107. The Progress 7K-TG spacecraft was the first generation Progress, derived from the Soyuz 7K-T and intended for uncrewed logistics missions to space stations in support of the Salyut programme. On some missions the spacecraft were also used to adjust the orbit of the space station.

The Progress spacecraft had a dry mass of 6520 kg, which increased to around 7020 kg when fully fuelled. It measured 7.48 m in length, and 2.72 m in diameter. Each spacecraft could accommodate up to 2500 kg of payload, consisting of dry cargo and propellant. The spacecraft were powered by chemical batteries, and could operate in free flight for up to three days, remaining docked to the station for up to thirty.

Launch
Progress 7 launched on 28 June 1979 from the Baikonur Cosmodrome in the Kazakh SSR. It used a Soyuz-U rocket.

Docking
Progress 7 docked with the aft port of Salyut 6 on 30 June 1979 at 11:18:32 UTC, and was undocked on 18 July 1979 at 03:49:55 UTC.

Decay
It remained in orbit until 20 July 1979, when it was deorbited. The deorbit burn occurred at 01:57:30 UTC and the mission ended at 02:40 UTC.