Why do Astronaughts appear to float in an orbiting space station?

Question

I have done resurch, but all i know is that there is less gravity. Thanks for your help!

Answer 1

because the space station is in orbit. an orbit is essentially a perpetual fall. falling causes weightlessness, therefore the astronauts are weightless

Answer 2

the astronauts appear to float inside the space station because, although they are orbiting the planet, they are also free falling towards earth, but going fast enough in a forward momentum that they 'miss' a collision with earth every time they circle...

Answer 3

No, gravity is still there. It remains the same. They are just in constant freefall inside a capsule. Much like in the aeroplane simulators that nosedive in the air to simulate weightlessness.

Gravity is everywhere....you have to go very deep into empty space to escape its forces.

Answer 4

Er... actually, gravity isn't "less". It's only apparent ''zero-gravity'. To experience the decrease of the force of gravity, you have to go to deep stellar space.

The reason why the astronauts happen to 'float' is because they're not the only ones experiencing gravity. What I mean is, their bodies AND their surroundings are equally accelerating under the force in the same direction. Therefore, the centrifugal force outward is counterbalancing the gravity force that pulls us inwards. So, the astronauts can't experience the effective force of gravity, but gravity doesn't decrease in any way. That's why it's only apparent.

It's really hard to explain that through something - it needs to be approached directly, but I hope that made sense...

Answer 5

Basically, orbiting bodies are falling toward the ground but keep missing.  It's that feeling of freefall that simulates a zero-gravity environment.

In fact, there's very little difference in gravity at that height.  On the ground, gravity is:

(6.67e-11)(5.9742e24/6378100^2) = 9.79541732 m/s^2

The ISS orbits at 340.5 km, so the gravity there would be:

(6.67e-11)(5.9742e24/(340500+6378100)^... = 8.82770924 m/s^2

This means that if you built a tower to the height of the ISS and stood on it, you would still feel about 90% of your normal weight.

Answer 6

Actually, the gravity is about the same.

Astronauts appear to float because they are falling at the same rate that the space station is falling.

Douglas Adams says flying is easy. All you have to do is throw yourself to the ground and miss. The ISS is moving fast enough to miss the Earth when it falls.

Answer 7

It's because they are in free fall (otherwise known as orbit) and therefore weightless. It's not that there is less gravity - it is gravity which is keeping them in orbit. If your mass is not actually pressing on something, like the earth, you are actually weightless (don't confuse mass and weight). Try jumping off a chair or table - you are actually weightless until you hit the ground,

Answer 8

they are falling to the earth at the same rate gravity pulls them down except cause of there altitude ,they never hit the ground and just continue falling over the horizon ,imagine if you were   on a very tall building (miles high) and could throw a ball over the horizon ,it would never hit the floor,tricky to get your head round

Answer 9

Simply because they are floating.

Answer 10

Orbiting ships are in a constant state of free fall, except they're also flying forward so fast that they keep missing the earth, constantly turning around it because the earth itself is round.

If you ever go on a plane that makes a deep dive towards the ground at just the right speed, you will also start to float. Look at this video: http://www.youtube.com/watch?v=7tEkKhMVo...

Answer 11

Weight is the normal force applied by the surface of the Earth on objects that are placed on it.

So, more the gravity more is the weight.

Also, when an object is in circular motion, it's velocity changes, hence it is accelerating, even if  there is no change in speed.

From Newton's second law, a force therefore is required to keep the object in a circular motion. When satellites move in orbits around Earth, it is the gravitational force that provides the required acceleration. This is the case even if it's not a circular motion, but an elliptical, parabolic or a hyperbolic motion.

When in an orbit around the Earth, if an object moves with it's orbital velocity, the gravitational force is exactly equal to the force required for the motion.

Hence, when the object comes into contact with any surface, as there is no force "pushing" it against it, there is no normal force, hence no weight.

Answer 12

There is not much gravity less than on the surface - it is just the fact that space station and astronauts are falling towards Earth with the same acceleration - they are in free fall.

They just don't crash into Earth, because they also travel so fast - they are so fast, that they always miss Earth while falling towards it.

Answer 13

Because, like the space station itself, they are in balance between the downward pull of gravity which does exist there, and the outward centrifugal force created by the circular orbit of the station.  If the station were to come to a stop, but not lose any altitude (hypothetically speaking), the astronauts would feel some gravity and drop to what would then be the "floor".