ISS space walk. Astronaut Michael Lopez-Alegria during a mission to continue the construction of the International Space Station (ISS). He is seen holding a 35mm camera as he orbits the Earth next to the Unity module (Node 1) of the ISS. The Space Shuttle Discovery flew this 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.