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Stationed in the Stars

Free-Falling Go to part 1 of Free-Falling

Shockwave required

by Rick Groleau

Ask someone why astronauts in the Space Shuttle or the MIR space station float in their cabins, and quite often you'll hear that it's because there's zero gravity in space. This kinda makes sense, doesn't it? After all, the space travelers are about hundred miles above the Earth's surface, right?

Actually, that answer is completely wrong. It is true that the pull of gravity is less on the astronauts and their craft, but the pull is only slightly less. With the center of the Earth 3,960 miles away from someone standing on the surface and 4,060 miles away from someone orbiting 100 miles above, the difference in the pull of gravity is only about 5 percent. That means if you weigh 100 pounds on Earth, you would weigh 95 when 100 miles high.

No, the real reason that astronauts float around is that they're in a continuous free fall. To find out exactly how this works, check out "the full explanation" below, starting with Part 1. If you want more of a challenge, skip right to "just the activities" and see if you can figure it out yourself.

The full explanation
    Part 1: Free-falling and weightlessness

    Part 2: Falling Far
        requires the Shockwave plug-in

    Part 3: Speed is key
        requires the Shockwave plug-in


Just the Activities
    Clear the Edge (from Part 2)
        requires the Shockwave plug-in

    Into Orbit (from Part 3)
        requires the Shockwave plug-in

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