The history of building and operating space stations in Earth orbit has followed two paths, which did not come together until the late twentieth century with the International Space Station. Russia (before 1991, the Soviet Union) has devoted its energies to building, launching, and operating expendable stations that could not be resupplied—a total of ten between 1971 and 1986. The United States, on the other hand, has focused on planning permanent space stations, launching only one prototype before International Space Station assembly began in 1998.

Salyuts and Mir: Soviet/Russian Space Stations

In 1903 Russian schoolteacher Konstantin Tsiolkovsky (1857-1935), the father of Russian spaceflight, described Earth-orbiting space stations where humans would learn to live in space. Tsiolkovsky hoped that these would lead to space settlements and Moon and Mars voyages. Nearly seventy years later, Soviet engineers moved Tsiolkovsky's dreams a step closer to reality by launching...