structural:summarization
Salyuts and Skylab

Having lost the race to the Moon, the USSR decided to concentrate on orbital space stations. During 1969 and 1970, they launched six more Soyuz flights after Soyuz 3 and then launched a series of six successful space stations (plus two failures to achieve orbit and one station rendered uninhabitable due to damage from explosion of the launcher's upper stage) on their Proton-K heavy-lift launcher in their Salyut program designed by Kerim Kerimov. Each one weighed between 18,500 and 19,824 kilograms (40,786 and 43,704 lb), was 20 meters (66 ft) long by 4 meters (13 ft) in diameter, and had a habitable volume of 99 cubic meters (3,500 cu ft). All of the Salyuts were presented to the public as non-military scientific laboratories, but three of them were covers for military Almaz reconnaissance stations: Salyut 2 (failed), Salyut 3, and Salyut 5.

Salyut 1, the first space station, was launched by the Soviets on April 19, 1971. Three days later, the Soyuz 10 crew attempted to dock with it, but failed to achieve a secure enough connection to safely enter the station. The Soyuz 11 crew of Vladislav Volkov, Georgi Dobrovolski and Viktor Patsayev successfully docked on June 7, and completed a record 22-day stay. The crew became the second in-flight space fatality during their reentry on June 30. They were asphyxiated when their spacecraft's cabin lost all pressure, shortly after undocking. The disaster was blamed on a faulty cabin pressure valve, that allowed all the air to vent into space. The crew was not wearing pressure suits and had no chance of survival once the leak occurred.

The United States launched a single orbital workstation, Skylab, on May 14, 1973. It weighed 169,950 pounds (77,090 kg), was 58 feet (18 m) long by 21.7 feet (6.6 m) in diameter, and had a habitable volume of 10,000 cubic feet (280 m). Skylab was damaged during the ascent to orbit, losing one of its solar panels and a meteoroid thermal shield. Subsequent crewed missions repaired the station, and the third and final mission's crew, Skylab 4, set a human endurance record (at the time) with 84 days in orbit when the mission ended on February 8, 1974. Skylab stayed in orbit another five years before reentering the Earth's atmosphere over the Indian Ocean and Western Australia on July 11, 1979.

Salyut 4 broke Skylab' s occupation record at 92 days. Salyut 6 and Salyut 7 were second-generation stations designed for long duration, and were occupied for 683 and 816 days.