0
It is a popular misconception that there is no gravity in space. In fact, the gravitational pull on astronauts in the International Space Station (ISS) is nearly the full amount (about 90%) of the gravitational pull on the surface of the earth. While in orbit around the earth, the ISS is free falling, and everything inside the ISS is also free falling. In true free fall you feel weightless, but there is still gravity that is causing you to fall.
.
Imagine you are in an elevator and the cables snap, and the elevator starts falling. Disregarding air friction, you and everyone in the elevator will all fall at the same speed as the elevator. You will be able to "float" weightlessly inside the elevator, just as astronauts do inside the ISS.
.
In the case of the elevator, we know eventually you will meet an untimely end when the elevator strikes the ground floor. But unlike the elevator, the ISS is also moving sideways at a very high speed, so as it falls downward, it also travels sideways, and so the ISS follows the path of a circle. The shape and size of this circle is such that the ISS never gets any closer to the earth, even though it is "falling". The ISS is free falling in an orbital path.
.
To understand how the ISS is free falling, follow this mental experiment. Disregard air friction, and assume you have unlimited strength. Imagine throwing a Baseball level to the ground - that is, you don't throw it up or down, but it is travelling parallel to the ground when it leaves your hand. We all know from experience the ball will travel a ways before falling to the ground. Now, throw it twice as hard. It will travel twice as far before hitting the ground. Now imagine being able to throw the baseball so hard that it lands 6000 miles (10,000 Km) away. But 6000 miles away is a quarter of the way around the spherical planet. So your ball did not go in a straight line - it was falling all the time it was in flight, but because the earth was curving away, the ball also travelled in a curved line while in free fell. Finally, imagine throwing the ball so hard that, as it fell downwards, the earth curved away at the same rate, and so the ball whizzed around the earth and hit you on the back of the head.
.
We know that a ball cannot hit you on the back of the head, even if you could throw it that hard, because of air friction and obstacles in the way, like mountains. But at 250 miles up, there is (almost) no air friction, and no obstacles to prevent the ball from circling the earth. That is exactly what happens to the ISS - the rockets push (throw) the ISS so hard and so fast in a sideways direction that, as the ISS falls, the earth curves away from it at exactly the same rate, and so the ISS really does fall without actually getting closer to the earth.
.
That is why when they make movies (like Apollo 13, directed by Ron Howard), they were able to duplicate true weightlessness. They put the actors in a set inside an jet airplane, and flew the airplane high up, cut the engines, and allowed the airplane, and everyone in it, to free fall for a while. During the airplane's free fall, everyone was weightless, exactly as if they were on the ISS.
.
Indeed, we know from Newton's first law of motion that a body in motion moves at the same speed and in the same direction unless a force acts upon it. So we know that the ISS would go in a straight line, NOT in orbit, if no forces were acting upon it. But it does follow a circular orbit, and so we know for certain that that full force of gravity is still acting upon the ISS and all of its occupants.
Wiki User
∙ 10y ago
Wiki User
∙ 6y agoThey are in free fall. That is, the ONLY force acting on them is gravity, and to them, that feels as if there were no gravity. Imagine the person next to a spacecraft - and both are orbiting Earth. The person accelerates towards Earth - but so does the spacecraft, and it does so at the same rate, so they stay close together, at least initially.
Wiki User
∙ 14y agothere is basically no gravity, so everything floats
Wiki User
∙ 14y agoPut it in a rocket and launch it into space
Wiki User
∙ 11y agomost likely because of gravity and gravtational force
Add your answer:
Earn +20 pts
What happens to old satellites?
Old satellites orbiting near the Earth eventually fall back into the atmosphere and burn. Satellites orbiting farther away stay in orbit indefinitely.
Why do artificial satellites not fall?
. The speed of the satellite is adjusted so that it falls to earth at the same rate that the curve of the earth falls away from the satellite. The satellite is perpetually falling, but it never hits the ground!
Why is it important for satellites to be outside the earths atmosphere?
Satellites need to be out of the earth's atmosphere or the gravity would make them fall to the ground. In space, the satellites are also able to orbit the earth effortlessly because they have less weight.
Why doun't satellites fall from the sky?
Interestingly enough the sattelites are doing their level best at falling from the sky. The whole idea is that at orbital velocity the objects move forward fast enough that they continously miss the Earth as they fall down. In the ideal case satellites are in orbit. This means that they circle the Earth at a specific speed and a specific height. Because satellites aren't in Earth's atmosphere nothing slows them down. If they did slow down it would reduce the height they orbit at. If the height were reduced they would encounter thicker air which would slow them down more, which would lower their height more. This cycle would continue until they crashed. In actuality the satellites do slow down very slowly because the air is not totally absent. Eventually all satellites will fall from the sky.
How do satellites move in orbit?
Satellite orbit the Earth at different altitudes. A good overview of Low Earth Orbit, Medium Earth Orbit and Geostationary Orbit can be found here: http://www.idirect.net/Company/Satellite-Basics/How-Satellite-Works.aspx
Why dont satellites in orbit fall to the ground like a ball in orbit?
They're given enough tangential velocity ('sideways' speed, parallel to the earth's surface) so that the curve of the earth falls away just as fast as the satellite falls.
Do satellites in orbit around Earth continuously fall toward earth?
Satellites orbit the earth for a few years then fall to earth however they are directed to fall to the sea
Why don't satellites fly into space?
Satellites, by definition, are in orbit. Which means that they're circling their host (planet). IF you were to increase their speed enough, they would. (And if you slowed it enough, then they would fall to the ground.)
Why don't satellites in orbit fall to the ground why don't the fly off in space?
that is because the 0 gravity keeps it in space and the orbit brings them around without knocking them down or anywhere else
What are the uses of old satellites?
Old satellites that are in orbit and still powered continue to perform their function. Old satellites that have no power and are still in orbit have no use. Those that fall from orbit have no use as the are destroyed on reentry. Old satellites that have never been launched could be used as museum exhibits.
What happens to old satellites?
Old satellites orbiting near the Earth eventually fall back into the atmosphere and burn. Satellites orbiting farther away stay in orbit indefinitely.
What are some problems that society's use of satellites may cause?
explosions if they fall out of orbit towards earth
Do satellities orbit Earth in the exosphere?
No. If they did, air resistance would quickly slow them down and they would fall out of orbit. In order to be in a stable orbit, the satellites must be out of the atmosphere completely.
What will happen when a satellite falls down?
When satellites fall out of orbit, they usual burn up upon entering the earth's atmosphere.
What happens to the old satellites?
If they are no longer used they will eventually fall from orbit and hopefully burn up in the atmosphere before hitting the earth.
Where satellites orbit?
Satellites orbit in several different regions of space in the sky. Orbits fall into 3 main categories based on distance: Low Earth Orbit (LEO) at an altitude of 160 - 2000 km, Medium Earth Orbit (MEO) at an altitude of 2000 - 35000 km, and High Earth Orbit (HEO) at altitudes greater than 36000 km. One special orbit in which a large number of satellites have been placed into is a geosynchronous earth orbit (GEO), which is at the exact distance such that the satellite orbits the earth at the same angular velocity at which the earth spins. Most satellites orbit in circular orbits. A few are in elliptical orbits in which their distance varies.
How does a rocket lift off the ground and what keeps a satellite in orbit?
A rocket can rise into the air because the gases it expels with a downward action force exert an equal but opposite reaction force on the rocket. Satellites in orbit around Earth continuously fall toward Earth, but because Earth is curved they travel around it.
