Home from Above . ... Credit Copyright: Expedition 18 Crew , NASA Explanation: There's no place like home . Peering out of the window of the International Space Station (ISS), astronaut Greg Chamitoff takes in the planet on which we were all born. About 350 kilometers up, the ISS is high enough so that the Earth's horizon appears clearly curved . ... The space station orbits the Earth about once every 90 minutes. ... Telescopes can even resolve the overall structure of the space station. ...