International Space Station seen over Earth from the approaching Space Shuttle Discovery during mission STS-92. This mission added new modules to the ISS. The modules seen here, before the additions, are, from top to bottom, Unity, Zarya, Zvezda and a Progress supply ship. The ISS is a collaboration between NASA, ESA, the Russian space agency, Canada, Japan and Brazil. When complete, it will be over four times larger than Mir, the Russian space station, and over 100 metres in length. It will orbit at an altitude of 400 kilometres. It is hoped to be completed in 2004.