Question

Astronauts floating around inside the space shuttle are not actually in a zero-gravity environment. Explain what is the real reason astronauts seem weightless.

Answer 1

Google "apparent weightlessness"

This site discusses this and even discusses the space shuttle...once you get past the ads.

http://www.popsci.com/military-aviation-%2526-space/article/2008-08/apparently-weightless

Answer 2

The reason why the astronauts are experiencing "weightlessness" is because the entire environment is falling at the same rate as the astronauts are.

When the shuttle the men are in is moving around the earth, it is "falling" around the earth in circular motion. It's moving forward because of its inertia, and the gravitational field is exerting a constant force that keeps it in orbit.

The men inside the shuttle are moving at the same speed as the shuttle, and relative to the shuttle, they are not moving at all! Weightlessness!

Answer 3

Astronaut motion in circular path of orbit . No downward or upward motion is active that is why .