Salyut 4

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Salyut 4 (DOS-4)
Salyut 4 diagram
Salyut 4 diagram
Station statistics
Call sign: Salyut 4
Crew: 3
Launch: December 26, 1974
04:15:00 UTC
Launch pad: Baikonur Cosmodrome, USSR
Reentry: February 3, 1977
Mass: 18,500 kg
Length: 15.8 m
Width: 4.15 m
Living volume: 90
Perigee: 136 mi (219 km)
Apogee: 168 mi (270 km)
Orbit inclination: 51.6 degrees
Orbital period: 89.1 minutes
Days in orbit: 770 days
Days occupied: 92 days
Number of orbits: 12,444
Distance travelled: ~313,651,190 mi
(~504,772,660 km)
Statistics as of de-orbit and reentry.
Configuration
Salyut 4 and Soyuz diagram
Salyut 4 and Soyuz diagram
Salyut 4 (DOS-4)

Salyut 4 (DOS 4) (Russian: Салют-4; English translation: Salute 4) was a Salyut space station launched on December 26, 1974 into an orbit with an apogee of 355 km, a perigee of 343 km and an orbital inclination of 51.6 degrees. It was essentially a copy of the DOS 3, and unlike its ill-fated sibling it was a complete success. Three crews attempted to make stays aboard Salyut 4 (Soyuz 17 and Soyuz 18 docked; Soyuz 18a suffered a launch abort). The second stay was for 63 days duration, and an unmanned Soyuz capsule remained docked to the station for three months, proving the system's long-term durability. Salyut 4 was deorbited February 2, 1977, and re-entered the Earth's atmosphere on February 3.

Contents

[edit] Instrumentation

Installed on the Salyut 4 were OST-1 (Orbiting Solar Telescope) 25cm solar telescope, designed at the Crimean Astrophysical Observatory, and two X-ray telescopes.[1][2] One of X-ray telescopes, often called the Filin telescope, consisted of four gas flow proportional counters, three of which had a total detection surface of 450 cm² in the energy range 2-10 keV, and one of which had an effective surface of 37 cm² for the range 0.2 to 2 keV (32 to 320 aJ). The field of view was limited by a slit collimator to 3° × 10° full width at half maximum. The instrumentation also included optical sensors which were mounted on the outside of the station together with the X-ray detectors, and power supply and measurement units which were inside the station. Ground based calibration of the detectors was considered along with in-flight operation in three modes: inertial orientation, orbital orientation, and survey. Data could be collected in 4 energy channels: 2 to 3.1 keV (320 to 497 aJ), 3.1 to 5.9 keV (497 to 945 aJ), 5.9 to 9.6 keV (945 to 1,538 aJ), and 2 to 9.6 keV (320 to 1,538 aJ) in the larger detectors. The smaller detector had discriminator levels set at 0.2 keV (32 aJ), 0.55 keV (88 aJ), and 0.95 keV (152 aJ).

[edit] Science

Among others, observations of Sco X-1, Cir X-1, Cyg X-1, and A0620-00 were published from the Filin data. A highly variable low energy of 0.6 to 0.9 keV (96 to 144 aJ) flux was detected in Sco X-1. Cir X-1 was not detected at all during a July 5, 1975 observation, providing an upper limit on the emission of 3.5e-11 erg·cm-2·s-1 (35 fW/m²) in the 0.2 to 2.0 keV (32 to 320 aJ) range. Cyg X-1 was observed on several occasions. Highly variable flux, in both the time and energy domains, was observed.

[edit] Specifications

  • Length - 15.8 m
  • Maximum diameter - 4.15 m
  • Habitable volume - 90 m³
  • Weight at launch - 18,900 kg
  • Launch vehicle - Proton (three-stage)
  • Orbital inclination - 51.6°
  • Area of solar arrays - 60 m²
  • Number of solar arrays - 3
  • Electricity production - 4 kW
  • Resupply carriers - Soyuz Ferry
  • Number of docking ports - 1
  • Total manned missions - 3
  • Total unmanned missions - 1
  • Total long-duration manned missions - 2

[edit] Visiting spacecraft and crews

  • Soyuz 20 - November 17, 1975 - February 16, 1976
    • no crew

[edit] Salyut 4 Expeditions

Expedition Crew Launch Date Flight Up Landing Date Flight Down Duration (Days) Notes
Soyuz 17 Georgi Grechko,
Aleksei Gubarev
January 11, 1975
21:43:37 UTC
Soyuz 17 February 10, 1975
11:03:22 UTC
Soyuz 17 29.56 Launch from Baikonur; landing 110 km northeast of Tselinograd; docking on space station Salyut 4, which had been launched 3 days earlier; transfer into space station and 29 days stay time there; astronomical experiments.
Soyuz 18 Pyotr Klimuk,
Vitali Sevastyanov
May 24, 1975
14:58:10 UTC
Soyuz 18 July 26, 1975
14:18:18 UTC
Soyuz 18 62.97 Launch from Baikonur; landing 56 km east of Arkalyk; 2. crew of spacestation Salyut 4; 62 days staying time; intensive fitness training; breeding of "space vegetable"; solar observation; taking photographs of Earth surface.

[edit] See also

[edit] References