How high do astronauts orbit the earth?

Every crew in space today is flying a few hundred kilometres up. The International Space Station keeps to roughly 400 km, lapping the planet in about 90 minutes, and China's Tiangong station sits in a similar band. That height is a compromise. Go much lower and the thin traces of atmosphere drag a station down quickly. Go much higher and two problems grow: the rocket works harder for every kilogram delivered, and the crew starts spending time in the inner radiation belt, where trapped particles make long stays unattractive.

Even at 400 km the drag never stops. The station loses altitude continuously and is pushed back up by visiting vehicles or its own thrusters, which also lets controllers raise the orbit to avoid tracked debris.

Crews have gone higher. Shuttle missions to service Hubble climbed well above the station's altitude, because the telescope was deliberately placed where the air is thinner. In September 2024 the private Polaris Dawn crew reached about 1 400 km, the highest Earth orbit flown with people aboard, crossing part of the inner belt on purpose so that radiation could be measured (data as of September 2026).

Apollo belongs in a different category. Those crews left Earth orbit altogether for the Moon between 1968 and 1972, so the greatest distance humans have reached from the planet has nothing to do with orbital altitude.

From 400 km the Earth still fills most of the window; the horizon curves but the planet is not a small blue marble. Crews cross a continent in minutes, see sixteen sunrises in a working day, and can pick out airport runways, wildfire smoke and city grids without instruments. It is close enough that a radio call to the ground carries no perceptible delay.