Sen—A close cousin of the Soyuz spacecraft, the Progress cargo ship was designed in the 1970s to resupply the Soviet space stations. It was launched for the first time on Jan. 20, 1978, and successfully docked at the Salyut-6 space station. Since then, the Progress has become a permanent fixture of the Soviet and Russian space program. The first 12 ships went to the Salyut-6 space station, enabling its expeditions to beat flight-duration records set by American astronauts onboard Skylab in 1973 and 1974.
Between 1982 and 1985, during the orbital tenure of the Salyut-7 space station, 13 Progress ships were sent to that orbital lab. Again, cargo deliveries were instrumental for extending the crew presence in orbit.
In 1986, the USSR launched the first modular space station called Mir, which operated in orbit until 2001. To resupply Mir, 18 cargo ships from the original Progress series (Series 100) headed to the station. In 1989, cargo delivery responsibilities were taken over by the Progress M variant (Series 200), featuring a new-generation flight control system.
During the 1990s, a new version of the spacecraft known as M1 was developed specifically for the International Space Station (ISS). Engineers repackaged the tanker section of the spacecraft to allow the delivery of more fuel to the ISS. Additional propellant tanks were also fitted into the middle section of the ship at the expense of water tanks, which were moved into the front cargo section of the vehicle. At the same time, 12 tanks for storing a nitrogen and oxygen mix to refill the station's atmosphere were placed on the exterior of the ship around the neck between the cargo and propellant modules (see infographic below). Lifting off on Feb. 1, 2000, the Progress M1 version was first flight-tested on a mission to the Mir space station. On August 6 of the same year, the first Progress spacecraft (M1-3) was launched to the nascent ISS.
A total of 80 Progress-M and M1 ships flew until the introduction of Progress M-M (series 400) in 2008. The series 400 upgrade featured a modern TsVN-101 digital flight control system, replacing an older Argon-16 computer. These upgrades empowered Progress with a faster and more efficient flight control system, while at the same time reduced the overall mass of avionics onboard the ship by 75 kilograms, and the number of avionics modules by 15.
A total of 27 Progress M-M vehicles have been launched to the ISS, however two of them never made it to the station due to failures of their Soyuz rockets. Progress M-12M was lost in August 2011 before it had a chance to reach orbit. Progress M-27M failed immediately after entering orbit on April 28, 2015. Although the third stage of the Soyuz rocket was blamed for both accidents, the investigation into the latest failure is still ongoing.
After 37 years in service, Progress ships have so far made a total of 151 missions (including 60 launches to the ISS), delivering more than 300 tons of propellant, water, food and other supplies to four orbital outposts.