Soyuz - astronomy.

Soyuz - astronomy. I INTRODUCTION Soyuz, piloted spacecraft used by Russia to transport crew members and supplies to space stations. Soyuz was first proposed in 1962 as part of the lunar program of the former Soviet Union. The first Soyuz flight carrying a cosmonaut (Soviet astronaut) was made in 1967. After the Soviets lost the race to put a person on the Moon in 1969, they redesigned Soyuz to be a ferry to their series of seven Salyut space stations and, later, to their Mir space station (see Space Exploration). Over the years, Soviet engineers improved the Soyuz spacecraft, producing the Soyuz Ferry (which flew from 1972 to 1981, bound for Salyut stations); the Apollo-Soyuz Test Project (ASTP) Soyuz (1974-1976, one of which docked with an American Apollo spacecraft); the Soyuz-T (1978-1986, bound for Salyut stations and for Mir); and the SoyuzTM (1986-2001, bound for Mir and the International Space Station). In all, more than 70 Soyuz spacecraft have carried cosmonauts into orbit. After the break up of the Soviet Union in 1991, Russia took over most of the former country's space programs, including the operation of Mir and the Soyuz spacecraft. II SPACECRAFT The Soyuz spacecraft weigh about 7 metric tons and have an oval orbital module in front, a bell-shaped descent module in the middle, and a cylindrical service module in the rear. The orbital module provides living space and carries the docking mechanism, which enables the craft to connect with other spacecraft in orbit. The descent module contains controls and seating for cosmonauts. It is the only part of the craft that returns to Earth. The service module carries rocket engines and the solar panels that are used for supplying electricity. The changing role of the Soyuz spacecraft has necessitated a variety of design changes. The docking mechanism was modified when the spacecraft was redesigned for the space-station program. It was further modified to enable Soyuz to dock with an Apollo spacecraft of the United States. The failure of certain Soyuz spacecraft also led to safety-related changes such as altering the spacecraft to accommodate cosmonauts in full pressure suits during reentry into Earth's atmosphere. Soyuz spacecraft are launched on Soyuz rockets, which consist of four first-stage booster rockets strapped to a core rocket and the second-stage booster. The boosters use liquid fuel composed of kerosene and liquid oxygen. The spacecraft are launched from Baikonur Cosmodrome in Kazakhstan (formerly part of the Soviet Union). The Russians now rent Baikonur for launches. Soyuz descent modules land by parachute. They landed in Kazakhstan until 1991, but since the collapse of the Soviet Union they have usually landed in southern Russia. III EARLY MISSIONS Soyuz spacecraft did not perform well during the first five years of operation. The first three unmanned Soyuz test flights failed. Under pressure to win the space race against the United States, the Soviets launched the fourth spacecraft, Soyuz 1, carrying cosmonaut Vladimir M. Komarov into orbit on April 23, 1967. Komarov was to dock his craft with Soyuz 2 but Soyuz 1 malfunctioned, and Komarov attempted to return to Earth. He perished when the parachute on his descent module failed to open after reentry. He was the first person to die in spaceflight. In October 1968, cosmonaut G. T. Beregevoi attempted to dock his spacecraft Soyuz 3 with the manned Soyuz 2 but failed. In January 1969, the manned Soyuz 4 and manned Soyuz 5 docked, two cosmonauts transferred from Soyuz 5 to Soyuz 4, and the two spacecraft then separated and returned to Earth. The dual flight was intended as a rehearsal for part of the planned Soviet manned mission to the Moon. In July 1969, however, after the United States Apollo 11 lunar module landed on the Moon, the Soviets shifted the mission of Soyuz spacecraft from lunar landings to serving the space stations. Soyuz 6, Soyuz 7, and Soyuz 8 flew together in October 1969. The launching of three spacecraft in three days and their simultaneous maintenance in orbit were notable accomplishments for the Soviet Union. Although Soyuz 7 and Soyuz 8 failed to dock with each other as planned, the cosmonauts of Soyuz 6 succeeded in testing equipment for future space stations. In June 1970 the 17-day Soyuz 9 mission helped prepare Soviet cosmonauts for long stays on space stations and included the first long-term scientific work performed by crew members during spaceflight. In addition, the cosmonauts thoroughly tested all mechanical systems of the craft and took numerous photos of Earth. 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. Contributed By: David S. F. Portree Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.