Mir was bolted together in orbit over ten years, one module at a time
Mir, Russian for peace or world, was the first space station assembled piece by piece in orbit. Between 1986 and 1996 seven pressurised modules were added, each swung into place by a robotic arm. Valeri Polyakov lived aboard for 437 days straight, still the longest single human spaceflight on record.
Earlier stations had been monolithic. Salyut 1 and Skylab were single modules that could not be resupplied, and Salyut 6 and 7 added docking ports so cargo ships could top them up. Mir opened a third generation: a core module that served mainly as living quarters, plus add-on laboratories, each designed for a particular purpose. A decree of 17 February 1976 authorised the project, and by 1978 the core had its final layout of one rear port and five in a forward sphere.
Politics set the schedule. Work stopped while resources poured into the Buran shuttle, then resumed with orders that the station be in orbit before the 27th Communist Party Congress opened in 1986. To make it, engineers shipped the core to Baikonur for testing, where 1,100 of its 2,500 cables needed rework. After a scrubbed attempt, it launched on 19 February 1986. The first crew, on Soyuz T-15, also flew across to Salyut 7, the only trip ever made between two stations.
New modules usually arrived on Proton-K rockets, docked at the front, and were then lifted by their Lyappa arm and pivoted 90 degrees onto a side port. Four modules joined this way, from Kvant-2 in 1989 to Priroda, the last, in 1996. Kvant-1, built originally for Salyut 7 and lacking engines, was towed to the rear in 1987, and Space Shuttle Atlantis delivered a docking module in November 1995. Outside, a 14-metre girder carried a thruster block whose leverage cut fuel use for orientation by 85 percent, and two telescoping cranes let spacewalkers reach every module.
The station orbited between 296 and 421 kilometres, circling Earth 15.7 times a day. Over its fifteen years it was occupied for twelve and a half, hosting 105 people from 12 countries and 80 spacewalks, usually with three aboard but ten during the STS-71 Shuttle visit. Its continuous occupation of 3,644 days remained unbeaten until the ISS beat it in 2010. Funding ran out and Mir was brought down in March 2001, after a lifetime cost estimated at $4.2 billion.
Source: Mir
