Does gravity effect astronauts in space shuttle?

Answer 1

Yes, it affects all objects in space (and all objects have a gravity of their own, that grows with size/"weight").

The reason why people talk about "zero gravity" in the space station and shuttle is because both the shuttle and the people inside it are affected by the same amount of gravity, so relatively they are falling at the same rate. Hence people inside the shuttle will not be moving towards the edge of the shuttle due to gravity.

Take a football (the shuttle) and a tennis ball (some people) and hold them at the same distance from the ground and then release them (withuot adding any force, just let go). You will see that both objects will be affected by gravity, but relatively the tennis ball and the football are moving at the same speed.

Now imagine that the tennis ball was inside the football and voilá, you have the shuttle scenario.

Obviously the space shuttle is not falling directly towards the earth, it is actually "falling past it" - something that scientists call "orbit".

Answer 2

Yes, gravity still affects astronauts inside a space shuttle because the shuttle and everything inside it are in orbit around the Earth, so they experience microgravity. However, the sensation of weightlessness occurs because the shuttle is in freefall towards Earth at the same rate as the astronauts, creating the feeling of weightlessness.