Salyut 1 was the first DOS long duration orbital station. The 'civilian' DOS station was built on basis of the military Almaz stations with the mission of beating the American Skylab in the space station race and to determine the usefulness of manned observation of the earth by 1974. 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.
DOS was started only when the Soviet moon project failed, in order to beat the American Skylab to orbit. It was created using spaceframes from the Almaz military station program.
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ckikilwai 2 years ago 2