Comment by HarHarVeryFunny

It's not lack of gravity - it's just that you and the space ship are both falling towards earth under the same gravitational acceleration, so your acceleration relative to the spaceship is zero. You don't need to be in space to experience this - in a "vomit comet" airplane used for training astronauts (and for photographing Kate Upton) you experience the same thing as the plane goes into freefall.

You would of course also experience the same thing if you were out in space far from any major gravitational attraction (almost "lack of gravity"), but obviously that's not the case with things like the ISS that we're used to seeing.