What is microgravity?
Also called: weightlessness, zero gravity
Microgravity is the floating sensation felt in orbit. It is caused by free fall, not by an absence of gravity — at the space station gravity is still about 88% as strong as on the ground.
“Zero gravity” is the common term and it is misleading. Gravity weakens with distance, but slowly: at the station’s altitude of roughly 420 km, g is about 8.6 m/s² against 9.81 at the surface.
Astronauts float because they and their spacecraft are falling together, so nothing presses against anything. A falling lift would do the same thing, briefly.
The prefix “micro” is doing real work: there are tiny residual accelerations from drag and from the station’s own movements, which matter to experiments.
See it happen
Space & OrbitsFalling foreverSource: International Space Station