Hi, I just recently posted this on the astrophysics forum but thought it would probably not quite fit so i decided to move it here. Hi, this is my first post. I have been trying to find an answer out of my own interest but is unable to do so. while searching I found this wonderful website. I hope you guys can help. I came across a series of questions today and one of the question asks "What keeps satellites in orbit?" The answer choices were inertia, free fall, and centripetal acceleration (I knew it wasnt inertia so im down to free fall and centripetal) I picked free fall. HOWEVER, the answer was actually centripetal acceleration. I think that, with the amount of speed and height, a satellite can travel faster than it can fall and thus continue try to fall but unable to do so because it is traveling too fast about the earth's curvature and thus experience continuous freefall. Can someone explain this? Thanks By the way, one of the results i came across is found on: http://www.boeing.com/companyoffices...light/iss.html Thanks for any explanation , im quite curious.