Salyut

Salyut:

see space explorationspace exploration,
the investigation of physical conditions in space and on stars, planets, and other celestial bodies through the use of artificial satellites (spacecraft that orbit the earth), space probes (spacecraft that pass through the solar system and that may or may not
..... Click the link for more information. ; space stationspace station
or space platform,
artificial earth satellite, usually manned, that is placed in a fixed orbit and can serve as a base for astronomical observations; zero-gravity materials processing; satellite assembly, refueling, and repair; or, possibly, as weapons
..... Click the link for more information. .

Salyut

(sal -yoot) A series of Soviet space stations launched into Earth orbit and visited and operated by crews of cosmonauts from the USSR and (usually) other Communist countries. The first station was launched in Apr. 1971. Others followed, Salyut–4 (1974–75), Salyut–6, and Salyut–7 being predominantly civilian in nature: in addition to medical, biological, and technological purposes, the stations served as platforms for terrestrial and astrophysical observations. Every Salyut was maneuverable in orbit, either by an engine on board the station or on a craft docked to it. When not carrying a crew, they were under automatic operation.

Salyut–6 was launched in Sept. 1977 and its program ended in July 1982. There were crews on board for a total of about two years: the last manned mission was completed in May 1981. There was a docking port at each end of the 15-meter long 19-tonne structure. Crews were transported to and from the station by Soyuz craft. Simultaneous use of the two docking ports allowed long-term and short-term visits to occur concurrently. Additional cargo and fuel were ferried to the station by unmanned Progress craft.

Salyut–7 was launched in Apr. 1982. Its exterior was similar to that of Salyut–6 but its interior had been modernized both in instrumentation and living conditions. There were several manned missions of long duration before Salyut–7 was abandoned in a high orbit in 1986 after the Mir space station was launched. Increased solar activity expanded the Earth's upper atmosphere, causing the orbit to decay, and the craft made an uncontrolled but safe landing in Feb. 1991 in Argentina.

Salyut

the name of a series of Soviet space stations, which, since 1971, have orbited the earth with cosmonauts on board and in automatic flight. On Apr. 19, 1971, the world’s first space station—Salyut—was put into an orbit with a perigee of 200 km, an apogee of 222 km, and an inclination of 51.6°. The orbit was corrected several times during the flight.

The station’s flight, which lasted approximately six months, consisted of several stages. In the first stage there was a docking and joint flight with the Soyuz 10 spacecraft, which was launched on Apr. 23, 1971, with crew members V. A. Shatalov, A. S. Eliseev, and N. N. Rukavishnikov on board. Tests were conducted on the systems for location, approach, and docking of the spacecraft and station. After 5 hr 30 min of flight, Soyuz 10 separated from the Salyut station and landed in the USSR. During the next 1½ months the station operated automatically; the condition and functioning of onboard systems were checked, the orbit was raised, and scientific data were received and processed.

The second stage of the space experiment began on June 6, 1971, when the Soyuz 11 spacecraft was launched with crew members V. N. Volkov, G. T. Dobrovol’skii, and V. I. Patsaev on board. After the docking and the transfer of the cosmonauts to the Salyut station, the world’s first manned space station was achieved. During their 23 days of flight the cosmonauts conducted astrophysical observations and tested onboard systems, assemblies, and scientific equipment in various modes of operation. Methods and independent orientation and navigation aids, as well as control systems for maneuvering the space complex in orbit, were refined during the flight. Especially important for the country’s economy were the cosmonauts’ visual observations and photographing of geological and geographical objects on the earth, atmospheric phenomena, and meterologi-cal conditions. The cosmonauts carried out diverse biomedical studies. Medical data showed that the cosmonauts remained in good health throughout the flight. The cosmonauts perished during the return to earth as a result of depressurization of the reentry vehicle.

After the separation of the Soyuz 11 spacecraft, the Salyut station continued operating automatically; scientific and engineering studies were conducted systematically, and the operation of the systems, assemblies, and scientific equipment under conditions of prolonged space flight was monitored. On Oct. 11, 1971, the final operations were carried out to recover the station from orbit. Upon deceleration, the station went into a descent trajectory, entered the dense layers of the atmosphere above an assigned region of the Pacific Ocean, and ceased to exist.

The total weight of the Salyut station when docked with the transport vehicle was 25.6 tons, including 18.9 tons for the orbiting module and 6.7 tons for the transport vehicle. The total weight of scientific equipment and instruments was more than 1.2 tons. The station was 23 m long in a docked state, and the orbiting module was 16 m long with a maximum diameter of 4.15 m. The maximum cross-sectional dimension of the station with the solar batteries extended was 11 m, and the volume of the pressurized compartments was approximately 100 m³.

The Salyut station (see Figure 1) consists of two pressurized compartments—the access tunnel and the work compartment—and one unpressurized compartment—the equipment compartment. The access tunnel is one of the station’s living compartments; it is 2 m in diameter and 3 m long and is designed for conducting scientific observations and experiments. The docking unit of the tunnel permits multiple dockings of the station with a transport vehicle in orbit and the transfer of cosmonauts through the porthole. Equipment for the temperature-regulation and the life-support systems and scientific instrumentation are housed inside the tunnel. Panels of solar batteries, antennas, sensing devices, assemblies for the temperature-regulation system, star-telescope modules, and other devices are housed on the outside. The access tunnel has an external covering of vacuum-shield heat insulation.

The work compartment is located in the middle section of the station and consists of two areas with diameters of 2.9 m and 4.15 m; the total length is 9.1 m. The compartment houses the station’s primary control instruments and assemblies, life-support and power-supply systems, radio equipment, and equipment for conducting scientific research and observations. It was here that the cosmonauts performed the basic operations of flight control and scientific research and observations, performed physical exercises, ate, and rested. The station’s central control post is located in the forward area. It is designed to allow two crew members to work at the same time in performing operations to orient the station, switch on the vernier engine, make some navigation measurements, and control the primary onboard systems. The station has a total of seven posts at various locations in the compartment. At these posts observations are made of the earth’s surface, biomedical research is conducted, and scientific and navigation instruments are used. The work compartment has 15 windows for work with orientation and navigation instruments and for photography and visual observation; it also has sleeping areas for the cosmonauts. Normal pressure, humidity, and temperature are maintained in the compartment, with an atmosphere similar in composition to that of the earth. Scientific equipment, antennas, sensing devices, and radiator panels for the temperature-regulation system are located on the outside.

Aft of the work compartment is the unpressurized equipment compartment, which houses the vernier engine with fuel supplies, actuating elements of the orientation system, primary and back-up thrusters, and various other assemblies and instruments. The vernier engine is designed to make orbit corrections and to maneuver during an approach. The thruster engines are used to turn, orient, and stabilize the station. The station has more than 1,300 instruments and devices on board. All the Salyut stations are of the same class, but they differ in certain design concepts and onboard equipment, depending on the specific mission.

On Apr. 3, 1973, the Salyut 2 station was put into an earth orbit with a perigee of 215 km, an apogee of 260 km, and an inclination of 51.6°. The objective of the flight was to refine the basic design, onboard systems, and station equipment for automatic operation. The test data received confirmed the design and planning concepts and the characteristics chosen for the primary systems. The flight of Salyut 2 was made in the automatic mode, and the station’s work was completed in April 1973.

On June 25, 1974, the Salyut 3 station was put into an earth orbit with a perigee of 219 km, an apogee of 270 km, and an inclination of 51.6°. The objective of the flight was to test further the improved design, onboard systems, and equipment and to conduct scientific and engineering experiments in the manned and automatic modes. On July 5, 1974, Salyut 3 docked with the Soyuz 14 spacecraft; the commander of Soyuz 14 was Pilot-Cosmonaut of the USSR P. R. Popovich, and the flight engineer was Iu. P. Artiukhin. The 15-day program of work on board the station was carried out in full. On July 19 the crew returned to earth, and Salyut 3 continued its flight in the automatic mode according to an assigned program. From August 26 to August 28, Salyut 3 made a joint flight with the Soyuz 15 spacecraft, during which scientific and engineering experiments were run to test the spacecraft’s automatic rendezvous system in different flight modes. On September 23 an automatic reentry capsule delivered research material from the station to the earth. The station’s flight lasted seven months, and its mission was completed on Jan. 24, 1975. The flight included engine tests and

Figure 1. Design plan of the first manned scientific space station—Salyut: (1) rendezvous radar system antennas, (2) solar battery panels, (3) antennas for radio telemetry systems, (4) windows, (5) Orion star telescope, (6) air regeneration unit, (7) motion-picture camera, (8) still camera, (9) equipment for biological studies, (10) refrigerator for food, (11) sleeping area, (12) tanks for water supply system, (13) waste collectors, (14) orientation system engines, (15) fuel tanks, (16) sanitation-hygiene module, (17) micrometeorite recording sensor, (18) treadmill, (19) work table, (20) central control post, (21) pressurization system tanks, (22) cosmonaut sighting unit, (23) engines of the Soyuz spacecraft

tests of the control, stabilization, navigation, power-supply (with rotating panels of solar batteries), temperature-regulation, life-support, and radio-communications systems. A series of scientific and engineering, biomedical, and national-economic studies and experiments was also conducted.

On Dec. 26, 1974, the Salyut 4 station was put into orbit around the earth. On Jan. 11, 1975, the Soyuz 17 spacecraft was launched to deliver cosmonauts to the station. Cosmonauts A. A. Gubarev and G. M. Grechko were on board the station from Jan. 12 until Feb. 9, 1975, and carried out a series of scientific and engineering and biomedical studies and experiments, including important astrophysical observations in various wavelength bands and biomedical studies of the influence of weightlessness on the human organism under conditions of prolonged space flight.

The experiment begun by the crew of Soyuz 17 was continued by the crew of Soyuz 18, which was launched on May 24, 1975. Cosmonauts P. I. Klimuk and V. I. Sevast’ianov spent 63 days in space. Studies were made of the physical processes occurring in the active regions of the sun, the earth’s atmosphere, and outer space. Engineering experiments were conducted to test new systems and instruments for future spacecraft and long-term space stations, and a series of new studies was conducted of the reactions of the human organism to extended space flight.

REFERENCE

“Saliuf’na orbite: Sb. Moscow, 1973.

A. A. EREMENKO