ISS space walk. Astronaut Michael Lopez-Alegria during a mission to continue the construction of the International Space Station (ISS). He is seen holding onto a handrail on the Unity module (Node 1) of the ISS. A docking unit (PMA-3, pressurized mating adaptor, blue, upper right) was installed earlier in the mission. Photographed from the Space Shuttle Discovery 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 above the Earth, and will be over 100 metres in length. It is scheduled for completion in 2004.