IV.

Later Missions

In most Soyuz space-station missions, the Soyuz spacecraft flies to a station, docks, and remains docked for weeks or months. Successive models have been able to remain docked for longer periods of time. The Soyuz Ferry, an early model, could remain docked to a Salyut space station for 90 days. The Soyuz-T spacecraft, developed after the Apollo-Soyuz Test Project, could remain docked for 120 days, and the Soyuz-TM spacecraft, used for missions to the Mir space station and to the International Space Station, can remain docked for 180 days. If crew members are scheduled to remain on the space station past the safe lifetime of their Soyuz spacecraft, a guest crew visits the station, returns to Earth in the old spacecraft, and leaves the more recent Soyuz spacecraft for the resident members to use on their return voyage.

In the first space-station mission, Soyuz 10 failed to dock with the space station Salyut 1 in April 1971. Soyuz 11 docked in June 1971, and cosmonauts Viktor Patsayev, Georgi Dobrovolski, and Vladislav N. Volkov lived on the space station for three weeks. They perished, however, during their return to Earth when their air supply escaped through a damaged valve in the Soyuz 11 descent module.

After a two-year hiatus, during which new safety mechanisms were added to the Soyuz spacecraft and were tested on Soyuz 12 and Soyuz 13, Soyuz 14 succeeded in docking with Salyut 3 on July 13, 1974. From January 1975 to September 1985, missions were completed to Salyut 4, Salyut 5, Salyut 6, and Salyut 7, including several visits to the space stations by international crews.

The goal of the Apollo-Soyuz Test Project, a collaboration between the Soviet Union and the United States, was to dock Soyuz 19 with the American spacecraft Apollo ASTP (see Apollo Program). Soviet and American engineers worked together to develop a new docking mechanism for Soyuz 19 that enabled the spacecraft to connect to an international docking module that had been added to Apollo ASTP. This module was also used as an air lock to accommodate the dissimilar atmospheres of the two craft. The Soyuz spacecraft was further modified to enable it to receive the high-frequency communication signals sent by the Apollo spacecraft. On July 17, 1975, the two spacecraft docked. They remained connected for two days, during which American astronauts Thomas P. Stafford, Deke Slayton, and Vance DeVoe Brand and Soviet cosmonauts Aleksei A. Leonov and Valery N. Kubasov made four crew transfers and conducted numerous scientific experiments.

The first three missions to the Mir space station by Soyuz-T and Soyuz-TM spacecraft demonstrated the crafts’ ability to carry out both novel and routine operations. Soyuz-T 15 was the first spacecraft to visit Mir, the last to visit Salyut 7, the first to transfer between two space stations, and the last of the Soyuz-T series of spacecraft. Soyuz-TM 2, the first manned Soyuz-TM spacecraft, carrying cosmonauts Alexandr Laveikin and Yuri Romanenko, docked with Mir. It was joined shortly afterward by Soyuz-TM 3, carrying Soviet cosmonauts Alexandr Viktorenko and Alexandr Alexandrov and Syrian cosmonaut Mohammed al Faris. Laveikin, Viktorenko, and al Faris returned to Earth in Soyuz-TM 2, leaving Romanenko, Alexandrov, and Soyuz-TM 3 on Mir.

Since 1978, citizens of Czechoslovakia, France, Mongolia, Cuba, the United Kingdom, and about 20 other countries have flown on Soyuz spacecraft. In March 1995, American astronaut Norman E. Thagard flew in Soyuz-TM 21 to Mir; he returned to Earth in July 1995 on the U.S. space shuttle Atlantis.

The collapse of the Soviet Union left Russia with less money and fewer resources for spaceflight programs than in the past. Nevertheless, Russia managed to keep the Mir space station continuously staffed with crew members delivered by Soyuz-TM spacecraft until 2000. Russia’s contribution to the International Space Station also includes using Soyuz spacecraft to ferry crew members to the station.