Configuration of the International Space Station Poster

The International Space Station (ISS) is an internationally-developed research facility, which is being assembled in low Earth orbit and is the largest space station ever constructed. On-orbit construction of the station began in 1998 and is expected to be finished in 2012. The station is expected to remain in operation until at least 2020, and potentially to 2028. Like many artificial satellites, the ISS can be seen from Earth with the eye. The ISS serves as a research laboratory that has a microgravity environment in which crews conduct experiments in biology, human biology, physics, astronomy and meteorology. The station has a unique environment for the testing of the spacecraft systems that will be required for missions to the Moon and Mars. The ISS is operated by Expedition crews, and has been continuously staffed since 2 November 2000—an uninterrupted human presence in space for the past 10 years and 260 days. As of June 2011, the crew of Expedition 28 is aboard.