Before the race to the Moon ended in 1969, both the Americans and Soviets were planning their separate futures in space. After the competitive short-term goals of human spaceflight had been met in the 1960s, many advocates of space exploration envisioned a permanent human presence in space. During the 1970s and 1980s, the United States and the Soviet Union took different approaches to human spaceflight. 

After the Apollo missions to the Moon, the United States began developing an entirely new vehicle, the Space Shuttle. They also used the last of the Apollo-era vehicles to launch an experimental space station, Skylab, in 1973, and to participate in a Soviet-American rendezvous in space, the Apollo-Soyuz mission, in 1975. 

The Soviets gradually pursued the goal of establishing a permanent presence in space as well. They adapted their Moon-era hardware to launch a number of orbital space stations called Salyut, using Soyuz spacecraft to ferry crews and supplies for missions of increasing duration. 

Salyut

In the 1960s during the race to the Moon, the Soviets began to build hardware that in the 1970s became the world's first space station. On April 19, 1971, the Soviet Union launched the world’s first space station, Salyut (“Salute”). Six improved Salyuts were launched during the next ten years. The Salyuts were designed to make human presence in space routine and continuous. In addition to doing scientific research and spacecraft maintenance, cosmonauts tested equipment that would make space stations more habitable. There were 32 missions to the Salyuts. The longest stay, aboard Salyut 7, was 237 days.  

Skylab 

In 1969, a space task group recommended to President Richard Nixon a space program to follow the missions to the Moon. The plan included a permanently occupied space station, a reusable shuttle spacecraft, and eventual missions to Mars. But because of increasing budget pressures these ideas received little political or public support. Only the Space Shuttle won favor and funding, and even that decision was controversial. When the last two Apollo missions were canceled, NASA used some of the remaining Apollo hardware for an experimental space station, Skylab, as an interim program before the Shuttle was ready to fly. 

Skylab was a crewed space station launched into Earth orbit by the United States in May 1973. It was made from the third stage of the Saturn V launch vehicle. A crew of three astronauts occupied Skylab during each of its three missions. The longest mission, which ended in February 1974, lasted almost three months. The Skylab missions obtained vast amounts of scientific data and they demonstrated to the American public that people could live and work productively in space for months at a time.   

Skylab was equipped with instruments and experiments to: 

• Observe the Earth to study natural resources and the environment 
• Observe the Sun to study high-energy solar activity 
• Study the effects of weightlessness on the human body and assess crew adaptation to long-duration spaceflight 
• Study materials processing in microgravity 
• Perform experiments submitted by students for a "Classroom in Space"

Because Skylab was a research laboratory, the makeup of the crew was different from that of Mercury, Gemini, and Apollo missions. All previous crew members had been pilots, except for one scientist on the last Apollo mission. The Skylab crew included both pilots and scientists. All Skylab crew members were trained to conduct scientific experiments, but the science pilot held overall responsibility for onboard research.

Skylab had four major units: the orbital workshop, airlock module, multiple docking adapter, and an Apollo telescope mount. When in orbit, the Skylab space station was 36 meters (118 feet) long. With a docked Apollo command and service module, it weighed about 90,600 kilograms (100 tons).  

While the one- and two-week Gemini and Apollo missions were like camping trips, a Skylab mission was more like living in a small house. Astronaut crews stayed for up to three months, so the orbital workshop was designed for “habitability.”  

Skylab was reasonably comfortable and spacious, with more amenities than previous spacecraft. Among the features especially appreciated by the crews was the large window for viewing Earth, the galley and mess cabin with a table for group meals, the private sleeping quarters, and a shower custom-designed for weightlessness. 

Twin solar array wing panels were folded against the orbital workshop for launch, one on each side. When Skylab reached orbit, the arrays extended, exposing solar cells to the Sun to produce 12 kilowatts of power.  

During the launch in May 1973, the micrometeoroid shield accidentally deployed too soon, jamming one solar array wing and damaging the other so badly that both the wing and the shield were torn loose from the workshop. As a result, Skylab had only one solar array wing. With clever engineering and improvisation, the effect of the damage was minimized, and planned Skylab operations were completed despite the reduction in power. 

Skylab was intended to be a temporary—not a permanent—presence in space. Abandoned in 1974, it reentered the Earth’s atmosphere in July 1979. Although most of the spacecraft burned up during reentry, scattered pieces landed in Australia and the southern Indian Ocean. 

Soyuz and the Apollo-Soyuz Test Project 

The Soyuz ("Union") was in use longer than any other crewed spacecraft. Designed during the race to the Moon in the 1960s, it first carried a cosmonaut into space in April 1967. Since then, the Soyuz and its subsequent generations—the Soyuz T and Soyuz TM—flew scores of crewed missions in Earth orbit. Soyuz was the workhorse of the Soviet and Russian space programs, with more than 100 cosmonauts flown in them on a variety of Earth-orbiting missions. Read more about the Soyuz spacecraft.  

In July 1975 two crewed spacecraft were launched into Earth orbit—one from Kazakstan and the other from Florida. They met in orbit. Their rendezvous fulfilled a 1972 agreement between the Soviet Union and the United States to participate in a joint venture in space. 

The Apollo-Soyuz Test Project marked a brief thaw in the Cold War and the first time that they two rivals cooperated in a human spaceflight mission. Control centers in Moscow and Houston exercised joint duties through a cooperative exchange of tracking data and communications. The crews visited each other's spacecraft, shared meals, and worked on various tasks during several days together in space. Read more about the Apollo-Soyuz Test Project. 

Mir 

The Soviet Union’s Salyut space station was succeeded by a modular space station, Mir, which was used for more than a decade as new laboratory and power modules were added. Launched in February 1986, the Mir was designed to house more cosmonauts on longer stays than the Salyut could support. Some crew members spent a year or more on Mir.

The core of the Mir was the “base block” living quarters, which had six docking ports for spacecraft and other modules. Mir could be expanded by adding laboratory equipment and modules, rearranged for different missions, and upgraded without abandoning the original core unit.  

The Mir space station was occupied for more than a decade, spanning the collapse of the Soviet Union. The most powerful republic in the Soviet Union, the Russian republic—where the Soviet capital was located—took on all Soviet space programs as their own when they became their own country known as the Russian Federation.  

In 1993 and 1994, the heads of NASA and the Russian Space Agency signed historic agreements on cooperative ventures in space. The two agencies agreed to form a partnership to develop an international space station and, in preparation for that project, to engage in a series of joint missions aboard the U.S. Space Shuttle and the Russian Mir space station. It was part of a multilateral agreement including the European Space Agency, Canada, Japan.  

The first docking mission of the Space Shuttle and Mir occurred in 1995. Unlike the one-time joint Apollo-Soyuz Test Project mission in 1975, the Shuttle-Mir mission signaled an era of continuing cooperation between Americans and Russians in space.  

The Russians methodically improved the habitability and reliability of space systems through a succession of space stations. Cosmonauts have been living and working in space almost continuously since 1971. 

With the end of the Cold War in the late 1980s and early 1990s, the two crewed spaceflight programs began to converge. The Americans and the Soviets—and later the Russians—began to work with each other rather than against each other. First with the Apollo-Soyuz Test Project, then in joint missions on the Space Shuttle and Mir, and most recently aboard the International Space Station (ISS). Competition has yielded to cooperation in space.