International Space Station /

The International Space Station (ISS) is an internationally developed research facility that is being assembled in low Earth orbit. The objective of the ISS, as defined by NASA, is to develop and test technologies for exploration spacecraft systems, develop techniques to maintain crew health and performance on missions beyond low Earth orbit, and gain operational experience that can be applied to exploration missions. The objective of the ISS, for the RKA, the Russian space agency, is a continuation of the "permanent Soviet human presence in low-Earth orbit". On-orbit construction of the station began in 1998 and is scheduled for completion by mid-2012. The station is expected to remain in operation until at least 2015, and likely 2028. With a greater cross-sectional area than that of any previous space station, the ISS can be seen from Earth with the naked eye. The ISS is by far the largest artificial satellite that has ever orbited Earth. The ISS serves as a research laboratory that has a microgravity environment in which crews conduct experiments in biology, chemistry, medicine, physiology and physics, as well as astronomical and meteorological observations.