 A Progress 7K-TG spacecraft | |
| Manufacturer | NPO Energia |
|---|---|
| Country of origin | USSR |
| Operator | NPO Energia |
| Applications | Space stations resupply |
| Specifications | |
| Regime | Low Earth |
| Design life | 33 to 75 days |
| Production | |
| Status | Retired |
| Built | 43 |
| Launched | 43 |
| Retired | 43 |
| Maiden launch | Progress 1 (1978) |
| Last launch | Progress 42 (1990) |
| Last retirement | Progress 42 (1990) |
| Related spacecraft | |
| Derived from | Soyuz 7K-T |
| Derivatives | Progress-M |
Progress 7K-TG (Russian:Прогресс 7К-ТГ,GRAU index11F615A15), was aSoviet uncrewed spacecraft used to resupplyspace stations inlow Earth orbit. Forty three flew,[1] delivering cargo toSalyut 6,Salyut 7, andMir.[2] It was the first version of theProgress spacecraft to fly, and spawned later derivatives including theProgress-M which replaced it, and the laterProgress-M1.
The Progress 7K-TG spacecraft was derived from the crewedSoyuz 7K-T ferry spacecraft, which had been designed for theSalyut programme. The descent module of the Soyuz spacecraft was replaced with a new section designatedOtsek Komponentov Dozapravki, or OKD. This contained fuel tanks and pumps used for refuelling the space station that it docked with. Like the Soyuz 7K-T, the Progress was not equipped withsolar panels, and instead relied on batteries for power. Early spacecraft had a design life of 33 days, including three in free flight, and the rest docked with a space station. Later spacecraft flew longer missions, with the longest,Progress 38, spending almost 75 days in orbit.[2]
The first Progress 7K-TG spacecraft,Progress 1, was launched on 20 January 1978. The first twelve spacecraft flew to Salyut 6, with the next thirteen, including theKosmos 1669 spacecraft - a Progress spacecraft which was given aKosmos designation and omitted from the sequence of Progress designations - going to Salyut 7. The last eighteen flew to Mir. With the exception ofProgress 20, all of the flights to Salyut stations were launched bySoyuz-U carrier rockets. Progress 20 and all of the Mir flights used the more powerfulSoyuz-U2 carrier rocket.[1][3] The last spacecraft,Progress 42, was launched on 5 May 1990. It was deorbited on 27 May 1990, breaking up in the atmosphere over thePacific Ocean at around 12:27 UTC.[2]
Some Progress 7K-TG launches used the payload fairing developed for theSoyuz spacecraft, including thelaunch escape tower, but with the motors in the tower removed, and no stabilisers on the sides of the fairing. Officially this was done to preserve the rocket's aerodynamic properties, however it was reported that on several flights the tower was used to support tests of theK-36Mejection seat under development for theBuran programme.[2] In addition to their regular cargoes, theProgress 7 spacecraft was used to transport theKRT-10radio telescope to Salyut 6, andProgress 17 delivered theIskra 3 satellite to Salyut 7 for deployment.[1]
| Early programme |  | |
|---|---|---|
| 7K series | ||
| Later series | ||
| Progress | ||
| Other derivatives | ||
