Space Stations, History of

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 the Salyut 1 space station.

Salyut 1 (1971) was the first of seven first-generation Soviet space stations. Three of these, including Salyut 2, failed before cosmonauts could occupy them. Cosmonauts flew to the orbiting stations aboard Soyuz spacecraft. Salyut 1 and Salyut 4 (1974-1977) were civilian; Salyut 2 (1973), Salyut 3 (1974-1975), and Salyut 5 (1976-1977) were military. The stations could not be resupplied, so they had limited lifetimes in orbit. In all, six crews lived and worked aboard Soviet first-generation space stations. The longest stay duration was sixty-one days.

The Soviets launched two second-generation space stations. Both Salyut 6 and Salyut 7 were largely civilian and included a second docking port. Soyuz spacecraft bearing visiting cosmonauts docked at the second port, as did automated Progress resupply spacecraft. Salyut 6 (1977-1982) received sixteen cosmonaut crews, including six long-duration crews and visiting citizens of seven countries. The longest stay duration on Salyut 6 was 185 days. Twelve Progress freighters delivered more than 20 tons of supplies, equipment, and fuel. Salyut 7 (1982-1991) received ten crews, including six long-duration crews, visiting citizens of two countries, and the first woman space traveler since 1963. The longest stay duration was 237 days. Salyut 7 was last staffed in 1986, and it underwent uncontrolled re-entry over Argentina in 1991.

A total of three prototype space station modules docked with Salyut 6 and 7, paving the way for the third-generation Mir station (1986-2001). Mir was the first station designed for expansion to add new capabilities. During its fifteen-year life span, Mir received the Kvant (1987), Kvant 2 (1989), Kristall (1990), Spektr (1995), and Priroda (1996) expansion modules, as well as the Docking Module (1995), which permitted U.S. space shuttle dockings. These additions boosted Mir's weight from 20.4 tons at launch to about 135 tons at re-entry. Mir received thirty-one Soyuz and sixty-four Progress spacecraft and hosted twenty-eight long-duration crews. The longest stay duration was 483 days. American space shuttles docked with Mir nine times. Citizens of twelve countries, including seven Americans, lived on Mir for up to six months. Mir was deorbited over the Pacific Ocean in March 2001.

Skylab: The U.S. Space Station

In 1959 the National Aeronautics and Space Administration (NASA) called for development of a space station by 1970. In 1961, however, President John F. Kennedy declared that putting a man on the Moon by 1970 should be NASA's main goal, delaying the station. It was the first of many postponements in NASA's space station plans.

A 1964 NASA proposal called for building space stations using Apollo program technology. This led to Skylab, the first U.S. space station. Skylab left Earth in May 1973 atop a Saturn V rocket similar to those that launched Apollo astronauts to the Moon. The rocket's third stage carried no fuel—instead, it was heavily modified to provide laboratory space and living quarters for three-person crews. Apollo spacecraft designed originally for lunar flights ferried astronauts to and from Skylab. Three crews lived on the station, achieving stay durations of twenty-eight, fifty-six, and eighty-four days.

Skylab was not designed for resupply or refueling, and could not boost itself to a higher orbit when its orbit decayed through friction with Earth's upper atmosphere. In July 1979 Skylab deorbited and was destroyed over Australia.

International Space Station

In 1969 NASA proposed building a space station in the late 1970s. A reusable space shuttle would deliver crews and supplies to the orbiting outpost. By 1971, however, budget cuts forced NASA to postpone space station work and concentrate on building the space shuttle, which first flew in April 1981.

With the shuttle flying, NASA again proposed a space station. Because the Saturn V was no longer in production, NASA planned to launch its station in many pieces in the cargo bay of the space shuttle. In January 1984 President Ronald Reagan called for a U.S. space station within a decade. He invited Europe, Japan, and Canada to help build it.

Unfortunately, NASA underestimated the cost and complexity of its station plan. Space Station Freedom, as Reagan named it in 1987, underwent a series of redesigns. One occurred after the Challenger disaster (in January 1986) showed that the shuttle could not fly as often as originally planned. Another occurred in 1991, after studies showed that building and maintaining Freedom would take most of the crew's efforts, leaving little time for scientific research.

In 1993 new U.S. President Bill Clinton considered canceling Freedom. Instead, he ordered another redesign and made Russian participation in the station the flagship of his policy of aiding the financially strapped Russians in exchange for assurances that they would not sell nuclear missile technology to other countries. The redesigned station was renamed the International Space Station. Though the NASA-Russia relationship was often difficult, the partners each had something the other needed: NASA had money and Russia had nearly thirty years of space station experience.

Russia launched the first International Space Station component, a propulsion module called Zarya, in November 1998. NASA paid for Zarya. The first U.S.-built module, called Unity, was carried to Zarya in the cargo bay of space shuttle Endeavour in December 1998. The Russian-built Zvezda Service Module arrived in July 2000, and the first crew, consisting of two Russians and one American, took up residence in November 2000.

see also Capsules (volume 3); International Space Station (volumes 1 and 3); Mir (volume 3); Space Stations of the Future (volume 4).

David S. F. Portree

Bibliography

Canby, Thomas Y. "Skylab: Outpost on the Frontier of Space." National Geographic 146, no. 4 (October 1974):441-503.

Caprara, Giovanni. Living in Space: From Science Fiction to the International Space Station. Willowdale, ON: Firefly Books, 2000.

Madison, John J., and Howard E. McCurdy. "Spending without Results: Lessons from the Space Station Program." Space Policy 15, no. 4 (November 1999):213-221.

Portree, David S. F. Mir Hardware Heritage. Houston, TX: NASA Lyndon B. Johnson Space Center, Information Services Division, 1995.

Internet Resources

Portree, David S. F. Mir Hardware Heritage. 1995. National Aeronautics and Space Administration. <http://spaceflight.nasa.gov/history/shuttle-mir/ops/mir/mirheritage.pdf>.