Copyright © 2007 Dorling Kindersley
A space station is a spacecraft designed to stay in orbit for many years. Conditions inside are carefully controlled: solar panels supply power, a comfortable atmosphere is maintained, and air and water are recycled. On board, astronaut-scientists conduct experiments, studying how the condition of weightlessness affects materials, people, plants, and animals. The INTERNATIONAL SPACE STATION is a project by many countries working together.
The United States launched its first space station, Skylab, in 1973. One of its solar panels was ripped off at launch, damaging the heat shield over the crew’s quarters. The first crew managed to repair the damage and stayed in orbit for 28 days. Later crews spent 56 and then 84 days on board.
In February 1986, Russia launched the first module of a space station that would remain in orbit for 15 years. It was named Mir (Peace). Five more modules were added over the years, carried into orbit by unmanned rockets. In 2001, Mir descended from orbit and broke up in the Earth’s atmosphere.
Circling in orbit 390 km (240 miles) above Earth is the biggest structure ever built in space, the International Space Station (ISS). The nations involved include the United States, the 14 countries of the European Space Agency, Japan, and Canada. The ISS has been built by assembling its separate parts in orbit.
Experiments in plant growth on the ISS are very important, as plants could become a food supply for long interplanetary flights of the future. Also, plants turn carbon dioxide into oxygen, and could filter air. The laboratories of the ISS are unique because experiments are carried out in conditions of microgravity (near weightlessness). This is giving new insights into many aspects of physics, chemistry, medicine, and biology.