Soyuz T-15

Soyuz T-15 was a landmark mission of the Soviet space program, notable for being the only crewed expedition to visit two separate space stations. Launched in March 1986, its two-man crew transferred from the newly launched Mir core module to the aging Salyut 7 station, performing critical work at both outposts. This unique mission bridged the eras of the Salyut programme and the new Mir complex, demonstrating advanced orbital rendezvous and station management techniques.

Mission overview

The primary objective of the mission was to commission the new Mir station and conduct an unprecedented inter-station flight to the dormant Salyut 7-Kosmos 1686 complex. This flight was planned to salvage valuable equipment and complete scientific experiments left aboard the older station. The mission utilized the versatile Soyuz-T spacecraft, launched atop a Soyuz-U2 rocket from the historic Gagarin's Start at the Baikonur Cosmodrome. The flight profile required precise orbital maneuvers to match orbits with two different stations, a significant challenge for TsUP mission controllers.

Crew

The crew consisted of two highly experienced cosmonauts from the Cosmonaut Corps. The commander was Leonid Kizim, a veteran of the Soyuz T-10 mission to Salyut 7, making his third spaceflight. The flight engineer was Vladimir Solovyov, also on his second flight after his previous long-duration stay on Salyut 7 during Soyuz T-10. Their extensive prior experience on the Salyut 7 station was crucial for the success of the complex transfer mission.

Mission highlights

After docking with Mir on 15 March 1986, the crew activated the new station's systems, becoming its first resident crew. On 5 May, they undocked from Mir and, after a 29-hour solo flight, successfully docked with the Salyut 7-Kosmos 1686 complex on 6 May. During their approximately 50-day stay at Salyut 7, they performed extensive maintenance, retrieved over 400 kg of experimental results and personal effects, and conducted materials processing experiments. They undocked from Salyut 7 on 25 June and returned to Mir the following day, completing the first and only transfer of a crew between two inhabited space stations.

Spacewalks

Two extravehicular activities (EVAs) were conducted during the mission, both from the Salyut 7 station. On 28 May, Leonid Kizim and Vladimir Solovyov spent 3 hours and 50 minutes outside to test the new ERA semi-rigid space suit and assemble a 15-meter experimental truss structure. A second EVA on 31 May lasted 5 hours, during which they performed welding, brazing, and metal coating experiments on the station's exterior, further testing the capabilities of the new Orlan-DMA suit.

Legacy and significance

Soyuz T-15 remains a unique achievement in the history of human spaceflight. It successfully concluded the operational life of the Salyut programme while inaugurating the new Mir station, which would go on to host numerous international crews including participants from the Interkosmos program and NASA. The mission demonstrated sophisticated orbital logistics and the feasibility of servicing multiple orbital assets with a single crew, concepts that would later inform operations for the International Space Station. The crew's work salvaging equipment from Salyut 7 provided invaluable engineering data for future long-duration missions.

Category:Soyuz programme Category:1986 in spaceflight Category:1986 in the Soviet Union Category:Human spaceflights Category:Mir expeditions