Monday, June 1, 1998 Published at 10:51 GMT 11:51 UK
Mir: space's veteran station
Mir: an old-timer in space...waiting to be retired
Russia's ageing Mir space station has had a checkered 12-year history with a series of technical problems dogging its last years of operation.
The station was launched in 1986 and orbits the Earth at an inclination of 51.6 degrees. It is at any time 400 kilometres (248 miles) above the surface of the planet.
Weighing 120 tons, it has completed many thousands of circumnavigations of the globe.
Human presence in space
The rationale behind Mir was to maintain a long-term human presence in space on a permanently crewed station.
It was also meant to be a preparatory and experimental base for the larger International Space Station (ISS) of the 21st Century. Indeed, its original five year life-span was extended by the ISS's need for a home base.
More than 60 astronauts and cosmonauts have worked on board. The astronauts have come from all over the world. They have been French, American, German, British, Bulgarian, Japanese, Canadian, Kazakh, Austrian, Syrian and even an Afghan.
The woman holding the long-stay record is the American researcher Shannon Lucid, who spent more than 180 days on Mir.
Crossroads in space
Mir has been at the centre of numerous missions to space. In its lifetime 80 spacecraft, among them Soyuz capsules, Progress transporters and American space shuttles, have docked at Mir, carrying replacement crews and bringing cargo.
Cosmonauts and astronauts are currently performing experiments in preparation for the construction of the ISS. These projects include life science and microgravity studies, space technology experiments, as well as Earth observation.
Mir was the first space station built for expansion and is made up of a series of modules including the core module where the crew live. The Spektr module houses the station's laboratory and is where most of Mir's electricity is generated. The other modules Kvant-1, Kvant-2, Kristall, and Priroda carry various instuments and life-support hardware.
The station has not been without its critics. Nasa, which has been collaborating with the Russians since 1995, when the first US Space Shuttle docked with Mir, has expressed serious concerns about its safety record.
The series of crises led the American House of Representatives to demand no further US astronauts be permitted to work on Mir until Nasa certified it met safety standards.