Misconception about zero gravity

Misconception about zero gravity

if i ask a question ,why the astronaut floats inside the space station or feels weightlessness ? most of the people says because at the space station gravity is zero,but it's absolutely wrong !!! although the gravity at the altitude of the Station is about as strong as it is on Earth's surface (it is about 90% of full gravity).
in fact,zero gravity doesn't exist at all.

Suppose you climbed to the top of a ladder that's about 300 miles tall (altitude of ISS). You would be up in the vacuum of space, but you would not be weightless at all. You'd only weigh about ten percent less than you do on the ground. While 300 miles out in space, a 100kg person would weigh about 90kg. Yet a spacecraft can orbit 'weightlessly' at the height of your ladder! While you're up there, you might see the Space Shuttle zip right by you. The people inside it would seem as weightless as always. Yet on your tall ladder, you'd feel nearly normal weight. What's going on?

The reason that the shuttle astronauts act weightless is that they're inside a container which is FALLING! If the shuttle were to sit unmoving on top of your ladder (it's a strong ladder,) the shuttle would no longer be falling, and its occupants would feel nearly normal weight. And if you were to leap from your ladder, you would feel just as weightless as an astronaut (at least you'd feel weightless until you hit the ground!)

So, if the orbiting shuttle is really falling, why doesn't it hit the earth? It's because the shuttle is not only falling down, it is moving very fast sideways (at 7.71 km/s at that altitude) as it falls, so it falls in a curve. It moves so fast that the curved path of its fall is the same as the curve of the earth, so the Shuttle falls and falls and never comes down. Gravity strongly affects the astronauts in a spacecraft: the Earth is strongly pulling on them so they fall towards it. But they are moving sideways so fast that they continually miss the Earth. This process is called "orbiting," and the proper word for the seeming lack of gravity is called "Free Fall." You shouldn't say that astronauts are "weightless," because if you do, then anyone and anything that is falling would also be "weightless."