Salyut 4

Russian manned space station. Four of the initial DOS-1 versions of a civilian Soviet space station were built using converted Almaz military stations. Launched 1973.

DOS-1 was launched as Salyut 1 on 19 April 1971. The triumph turned to tragedy when the Soyuz-11 crew died due to de-pressurization of their re-entry capsule during return to the earth. Launches of the first series DOS stations continued in a desperate effort to beat Skylab into orbit with a fully successful Soviet space station mission. DOS-2, s/n 122, was destroyed in a launch vehicle explosion en route to orbit in July 1972. DOS-3, s/n 123, reached orbit as Cosmos 557 in 1973 but control was lost before a crew could be sent to the station. DOS-4, the last of the first series, finally flew successfully as Salyut 4 in 1974. Salyut 4 differed from Salyut 1 in having three sets or rotatable solar panels, more electrical power, and a more complete equipment suite.

Salyut 4 represented the second phase of DOS civilian space station. It had 2,000 kg of scientific equipment and two sets of 3 solar panels. It was equipped with the Delta navigation system. Experiments: - Solar telescope OST-1 with main mirror of 25 cm diameter, 2.5 m focal length, built by Crimean Astrophysical Observatory with spectrograph shortwave diffraction spectrometer for far ultraviolet emissions, oriented by maneuvering entire station - two X-ray telescopes - swivel chair for vestibular function tests - lower body negative pressure gear for cardiovascular studies - bicycle ergometer integrated physical trainer (electrically driven running track 1 m X .3 m with elastic cords providing 50 kg load) - penguin suits and alternate athletic suit - 15 medical experiments total - sensors for temperature and characteristics of upper atmosphere ITS-K infrared telescope spectrometer and ultraviolet spectrometer for study of earth's infrared radiation - multispectral earth resources camera - cosmic ray detector - embryological studies - new engineering instruments tested for orientation of station by celestial objects and in darkness - New autonomous navigation system calculates orbital elements without assistance from ground - teletypewriter - two spherical airlocks near main camera to ejects body wastes. Interior floor area: 34.8 sq. m

RCS Coarse No x Thrust: Verniers: 4 X 98 N - Pitch: 2 X 59 N - Yaw: 2 X 59 N - Roll: 2 X 20 N. RCS Fine No x Thrust: 18 x 10 N. RCS Coarse Backup No x Thrust: 4 x 98 N. Spacecraft delta v: 320 m/s (1,040 ft/sec). Electric System: 2.00 average kW.