The International Space Station as seen from the departing Space Shuttle Discovery during STS-119.
From Wikipedia.
The International Space Station (ISS) is a research facility currently being assembled in Low Earth Orbit. On-orbit construction of the station began in 1998, and is scheduled to be complete by 2011, with perations continuing until around 2015. As of 2009, the ISS is the largest artificial satellite in Earth orbit, larger than any previous space stations. The ISS program is a joint project among the space agencies of the United States, Russia, Japan, Canada and ten European nations.