Framed by the Earth's horizon and airglow, the full moon floats in the blackness of space in this photo from the Expedition 10 crew on board the International Space Station. The station plays a crucial role as an orbital outpost, as NASA pursues an exploration strategy that will send humans back to the lunar surface and eventually on to Mars and beyond. The International Space Station (ISS) is a space station, or a habitable artificial satellite, in low Earth orbit. Its first component launched into orbit in 1998, and the ISS is now the largest artificial body in orbit and can often be seen with the naked eye from Earth.