TKS-VA (11F74)

TKS-VA

The TKS-VA (Transportniy Korabl Snabzheniya - Vozvrashemui Apparat) reentry capsule was the reentry module of the TKS (FGB) spacecraft. The VA was capable of 31 hours of autonomous flight after separation from the TKS. A crew of three could be carried. Access to the TKS on the pad was through a square hatch in the side of the capsule, which could also be used to conduct EVA's in orbit, with the VA acting as an air lock for the TKS. The TKS could be accessed via a hatch in the heat shield below the middle seat. With the crew, 50 kg of payload could be returned. Uncrewed 500 kg of payload could be returned.

The BSO (Bloka Skhoda s Orbiti) housed the retro-rocket for deorbit of the VA capsule following separation from the space station. It was unusually mounted at the nose of the spacecraft. It also provided the additional battery power, orientation rockets, and radio equipment that gave the VA a 31 hour autonomous flight duration after separation from the TKS orbital module.

The VA capsule had a hypersonic lift to drag ratio of 0.25, which allowed the BSU-V crewed capsule guidance system to manoeuvre the spacecraft to its landing point using the optimum path for minimal heating and deceleration. Once the capsule was subsonic a drogue parachute deployed for seven seconds, followed by the 1770 square meters main chute. The capsule made a soft landing using a retrorocket in the parachute lines, triggered by the Probki radioactive sensor system within the Kaktus gamma ray altimeter.

For initial tests, the VA was launched without the TKS in pairs for one or two orbit missions. In these double launches, only the upper spacecraft had a rescue rocket system.

Originally crewed tests were planned, flying a crew in the upper VA, but this plan was dropped due to reliability problems of the Proton-K carrier rocket.

The name "Merkur", which is regularily reported for this capsule, is based on a translation error and was never allocated to the VA.

The first test flight launched two spacecraft together. Kosmos 881 (VA #009P) and Kosmos 882 (VA #009L) both reentered successfully.

On the second mission on 4. August 1977, both spacecraft VA #009P and VA #009L were again flown. During the launch phase forty seconds into the flight, the Proton-K rocket failed. While the upper spacecraft was successfully rescued by the abort system, the second in the lower position was lost.

The third mission on 30. March 1978 was successful. Kosmos 997 (VA #102P) and Kosmos 998 (VA #102L) both reached orbit and were successfully recovered.

On 20. April 1979 the fourth mission was to be launched, but the Proton carrier rocket suffered an on pad abort and did not lift off. The rescue rocket of the upper capsule (VA #103) was fired, but the parachute failed and the capsule was lost. The lower capsule (VA #008) remained on the rocket. The rocket was reused for the final mission. Originally the mission was to be flown with a crewed upper capsule, which was changed to an uncrewed flight due to reliability issues with the carrier rocket.

The final mission on 23. May 1979 was successful. Reusing the rocket from the fourth attempt and the VA spacecrafts of the third mission, it launched Kosmos 1100 (VA #102P) and Kosmos 1101 (VA #102L) into orbit. Both capsules were recovered successfully.

Three more VA capsules were flown as part of the TKS spacecraft on Kosmos 929, Kosmos 1267 and Kosmos 1443. All three were successfully recovered. Another VA was part of Kosmos 1686, but was modified, so that it could no longer be separated or perform reentry.