TKS ( spacecraft ) The TKS spacecraft ( , , " Transport Supply Spacecraft " , GRAU index 11F72 ) was a Soviet spacecraft conceived in the late 1960s for resupply flights to the military Almaz space station . The spacecraft was designed for both crewed or autonomous uncrewed cargo resupply flights , but was never used operationally in its intended role – only four test missions were flown to Salyut space stations during the program . However the Functional Cargo Block ( FGB ) of the TKS spacecraft would later form the basis of several space station modules , including the Zarya FGB module on the International Space Station . The TKS spacecraft consisted of two spacecraft mated together , both of which could operate independently : While the VA carried the reentry hardware , and only minimal life support and maneuvering systems , the FGB would have been used as the primary orbital maneuvering system and cargo storage for the TKS spacecraft . The FGB could also be used alone as an unmanned cargo module without an VA spacecraft , which enabled the FGB design to be re - purposed as FGB space station modules later on . The VA spacecraft on the other hand was also intended to be launched as " Almaz APOS " , mated with an Almaz - OPS space station core as the primary orbital maneuvering system , instead of a FGB . , Excalibur Almaz planned to use the VA capsule as low - cost cargo return vehicles . Design . The TKS spacecraft was designed by Vladimir Chelomei as a manned spacecraft launched with Proton rocket alternative to the Soyuz spacecraft for use with " Almaz " space stations . Development began in 1965 , however the " Almaz programme " had been abandoned by the time the first TKS spacecraft flew in 1977 . The VA spacecraft ( " " Vozvrashaemiy Apparat " " ) was flown separately on four test missions with two craft per launch to test the design , as well as one " all - up " test mission and three resupply missions . It was never flown manned , although in December 1978 formation of a special group of six cosmonauts was approved for manned missions on board the TKS spacecraft . The project had further evolved with space station " " Modulny " " ( " " Modular " " ) based on the TKS design outline , reworked to dock with Salyut 7 , Mir and ISS space stations . This development was designated FGB , or Functional Cargo Block . The TKS spacecraft consisted of an 11F74 " Vozvraschaemyi Apparat " ( or " Return Vehicle " commonly referred to as the VA ) , attached to an 11F77 " Transportniy Korabl Snabzheniya " ( " Functional / Cargo Block " module or FGB ) . TKS VA . The TKS VA spacecraft was itself a very compact and efficient spacecraft . Typically it would reenter the atmosphere within 2 orbits , but could fly autonomously for up to 31 hours . The pressurized crew re - entry capsule was equipped with its own environmental control system , and topped with reaction control system , de - orbit braking engine , parachute system , and soft landing engines . Although extensively flight tested , it never flew with a crew on board . The VA design was derived from the planned capsule for the Chelomei ' s LK - 1 manned circumlunar spacecraft of the 1960s . It was also the basis for Chelomei ' s LK - 700 Lunar Lander crew capsule . The VA looked somewhat similar to the Apollo capsule , but was 30 % smaller than its NASA counterpart . TKS FGB . The FGB was entered from the VA spacecraft via a short tunnel . At the aft end a pilot station was equipped with controls and windows for manual docking with the Almaz space station . The docking port was also located here . Operational TKS spacecraft would have delivered KSI film return capsules to Almaz stations . These would have been stored around the docking port for transfer to the film capsule airlock for loading . Missions . VA spacecraft test flights . Four flights with eight VA spacecraft without an FGB module were conducted to speed up the development of the TKS spacecraft : TKS - 1 ( Kosmos 929 ) . Kosmos 929 was the first flight of a " complete " TKS spacecraft ( VA spacecraft with FGB ) , launched on July 17 , 1977 – it was a " solo " test flight and was not destined for a Salyut space station . The VA capsule returned to Earth August 16 , 1977 . The remainder of the spacecraft – the FGB – deorbited on February 2 , 1978 . TKS - 2 ( Kosmos 1267 ) . On April 25 , 1981 , TKS - 2 was launched unmanned as Kosmos 1267 , the first FGB to dock with a space station . After separation and recovery of the VA capsule on 24 May 1981 , the FGB docked on June 19 with Salyut 6 , after 57 days of autonomous flight . It remained attached to the station until both deorbited and were destroyed on 29 July 1982 . TKS - 3 ( Kosmos 1443 ) . On 2 March 1983 , TKS - 3 was launched unmanned as Kosmos 1443 . This time , the VA remained attached and the first " complete " TKS docked to Salyut 7 two days after launch . TKS - 3 separated from the station on 14 August . After undocking , the FGB and the VA spacecraft separated and the VA spacecraft continued in space for four more days demonstrating autonomous flight , before the VA capsule successfully re - entered on 23 August 1983 , landing 100 km south - east of Arkalsk and returning 350 kg of material from the station . The FGB deorbited itself on 19 September 1983 . TKS - 4 ( Kosmos 1686 ) . TKS - 4 was launched unmanned as Kosmos 1686 on 27 September 1985 . The landing systems , ECS , seats , and manned controls were removed from the VA spacecraft , and instead other payload was installed : a high - resolution photo apparatus , an infrared telescope and the " Ozon " spectrometer ) . The TKS successfully docked with Salyut 7 . The " military " long duration crew Salyut 7 EO - 4 , consisting of Viktor Savinykh , Alexander Volkov and the comannder Vladimir Vasyutin , had manned Salyut 7 that month to conduct experiments with TKS - 4 . However commander Vasyutin fell ill soon after arriving at the station . Originally scheduled to have a six month stay aboard Salyut 7 , Vasyutin ' s illness forced the crew to make an emergency return to Earth on November 21 , 1985 , preventing the crew from finishing the TKS experiments . The crew of Soyuz T - 15 returned to Salyut 7 in May 1986 , to conclude some of the experiments and ferry equipment to the then new Mir space station . Salyut 7 was moved to a higher orbit after that mission , while awaiting another ' TKS ' crew – there were even plans to return using the Buran shuttle . Such flights never materialized however beore Salyut 7 and Kosmos 1686 deorbited on 7 February 1991 , burning up together in a fiery show over Argentina . Further usage . The TKS design , which has never been flown manned , has gone on to provide the basic structure for several space future space station components , such as : TKS / Almaz VA capsules are presently being modernized for commercial use , by the private spaceflight company , Excalibur Almaz . Gallery . TKS based and descendant spacecraft and modules .