Salyut 1 (DOS-1) (Russian: Салют-1; English translation: Salute
1) was the first space station of any kind, and the first Soviet
space station. It was launched on April 19, 1971 (the day my
daughter was born!). Its first crew launched in Soyuz 10 but was
unable to board it due to a failure in the docking mechanism;
its second crew launched in Soyuz 11 and remained on board for
23 productive days. However, a pressure-equalization valve in
the Soyuz 11 reentry capsule opened prematurely when the crew
returned to Earth, killing all three cosmonauts. Salyut 1 re-
entered Earth's atmosphere on October 11, 1971. At launch, the
announced purpose of Salyut was to test the elements of the
systems of a space station and to conduct scientific research
and experiments. The craft was described as being 20 m in
length, 4 m in maximum diameter, and 99 m³ in interior space
with an on-orbit dry mass of 18,425 kg. Of its several
compartments, three were pressurized (100 m³ total), and two
could be entered by the crew. The first