ISS space walk. Astronaut William McArthur during a mission to continue the construction of the International Space Station (ISS). He is holding onto the end of the Space Shuttle Discovery's remote manipulator system (RMS) robotic arm. Earth is seen at bottom and PMA-2 (a pressurized mating adaptor), one of the ISS's docking units, is seen at top. Photographed on 15th October during mission STS-92 (11th-24th October 2000). The ISS is a joint effort between NASA, the European Space Agency, the Russian space agency, Canada, Japan and Brazil. It orbits at an altitude of 350 kilometres and will be over 100 metres in length. It is scheduled for completion in 2004.