SpaceShipOne did it! X Prize has been won.

[PyRo]

Sure, but there is still a very significant amount of gravity affecting things in orbit...that is why they stay in orbit.

Well yes, they are being pulled towrds the earth, the moon, the sun, and their is probably an inmeasurably small gravitational attraction between just about any two planets/stars.

[vf-xx]

Erm. Zero-G in orbit is due to you being constantly falling and missing the earth. If the gravity feild of Earth is strong enough to keep the moon nearby, then I'd say that there's plenty of gravity in low orbit. I mean, heck, you've heard of tides right? Caused by the interaction between the moon's gravity and the earth's?

[PyRo]

I don't think anyone actually said that thier was no gravity in space.

[OysterBoy]

While Zero G can be achieved I don't agree thats the same as weightlessness or lack of gravity. A short period of simulated is what you realy get there. Parabolic dives produce a short period of it... but actually having low to no gravitational pull for prolonged periods is not going to happen in those. .

Damn you and your 'science' and your 'facts'...

[RobAGD]

actally there was a thing on tv recently ( like in the last 2 weeks ) where the Vomit Comet trips could be bought for something in the 3k range. No Idea how long that is for but it was rather intresting seeing a reporter toss his cookies :)

and orbital gravity is refered to micro gravity.

Spriffy stuff.

-R

[Deep Sixx]

The further from earth you get the less gravity there is. You actually weight slightly less ontop of a high mountain then you do at sea level. So while there is gravity in orbit their isn't much, how do you think satalites work? They arn't burning an engine to keep them from falling.

What goes up don't always come back down.

Actually, that's not right at all. As long as the planet's mass is under you, you will still feel the pull of it's gravity. The less mass under you, the weaker the gravity. On top of Mt Everest, or at sea level, the Earth's mass is still under you and still pulling you down. To lessen the gravity, you must decrease the mass below you. Gravity's force will decrease as you go DOWN, as there is less mass below you. You would actually weigh less if you went to the center of the earth (intense heat & crushing pressure not withstanding ). So... start diggin'!! That's why you'd weigh less on the moon... the moon has less mass than Earth. Same with Mars. Jupiter has much more mass so you would be heavier (MUCH heavier), although Jupiter is a gas giant and has no actual surface to stand on.

There is no such thing as zero-gravity. You are always under the influence of gravity from something. The moon orbits the earth due to our gravity, the Earth orbits the sun because of the Sun's gravity, and the Sun orbit's the center of our galaxy due the gravitational pull of a massive black hole. Our galaxy is even under the influence of gravity from other galaxies... and the closest one is Andromeda... and that's over 2 million light years away!!

You cannot escape gravity. Astronauts seem weightless because they and their spacecraft are free falling back to earth. In orbit, however, you are high enough that you keep missing the planet, so you just keep falling. Same with satellites... forever falling.

sixx

[cphilip]

Even in orbit you are not in a situation with a lack of gravity, it is still quite strong...If i am not mistaken you feel weightless for the same reason you do in the planes, because you are falling.

thats why I said "Low or no gravitational pull". You would still have a small amount of gravity depending on your proximity to a gravitational body.

[SlartyBartFast]

thats why I said "Low or no gravitational pull". You would still have a small amount of gravity depending on your proximity to a gravitational body.

Gravity around Earth is enormous. "weightless" does not equate to a lack of gravity. You've only escaped Earth's gravitaitional pull once you LEAVE orbit.

Think of the force keeping the moon in orbit. Swing a weight around your body on the end of a rope. Then, try and fathom the gravitational pull that balances a mass the size of the moon travelling at 7.68 km/s!

[Restola]

Stop your forward motion and you'll quickly find out how "weak" Earth's gravity is in orbit.

[rkjunior303]

When you are in Orbit, you aren't still falling back to space.. The whole idea behind it is because you are accelerated to the point where you are moving too fast for the Gravity (as little/great of a pull) to pull you back to earth. Since you are in a vacuum, once you reach that velocity there is no resistance to slow you down -- therefore, you remain in 'orbit.' Unless an outside force, such as thrusters from the shuttle, changes that said speed -- you could be in orbit forever (satellites).

[SlartyBartFast]

When you are in Orbit, you aren't still falling back to space.. The whole idea behind it is because you are accelerated to the point where you are moving too fast for the Gravity (as little/great of a pull) to pull you back to earth.

Of course gravity is pulling you back to Earth. If it wasn't, you wouldn't stay in orbit and would fly off into the depths of space. And, you could consider it "falling" towards Earth. It's just that at the right speed, an object in orbit moves "forward" and away from the Earth at the same rate at which its velocity is accelerated towards Earth. Net result: same distance from ground, remain in orbit.

Spin a weight on the end of a rope. What happens if you let go? While spinning, the rope is the equivalent of Earth's gravity (or more acurately, the interaction and mutual attraction between the mass of Earth and the mass of the object in orbit).

It's a balance between of forces, centripetal versus gravity.

[Deep Sixx]

Some of you are confusing "weightlessness" with "zero-gravity". In orbit, you are weightless because you are in permanent freefall. You are being pulled back to Earth by gravity, but you are so high and moving so fast, you continually miss the planet. This is called near-earth orbit. If you continue to accellerate away from the planet, the pull of the Earth's gravity will decrease, but by the time you were far enough away from Earth to COMPLETELY escape its pull, you'd be under the influence of something else's gravity... like Mars. Even on the moon, you are still pulled by Earth... otherwise the Moon would orbit the Sun, not us. Yeah, ok... the moon does technically orbit the Sun too, but you know what I mean.

You cannot escape gravity.

sixx