Gravity on the International Space Station is actually about 90 per cent of gravity on the ground
Orbiting at an altitude of only 400km above Earth, the International Space Stations (ISS) is so close to our planet that gravity barely differs from what is experienced on the ground. Astronauts are weightless for the same reason as someone unfortunate enough to be in a lift after its cable has snapped – because, as fast as they fall towards the lift floor, the lift floor falls away from them. It is not obvious that the ISS is falling. That is because it has sideways motion. This means that, as fast as gravity curves its path down towards the Earth’s surface, the Earth’s surface curves away from it. ISS therefore falls forever in a circle, never reaching the