How does it use to move forward?
2007-10-11 04:45:34 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
You are probably thinking of the latest Dawn space probe that uses ion engines.
The electric energy generated by the solar panels is used to ionize the Xenon gas. It is also used to produce a high voltage which is applied to an anode screen and a Xenon emitter assembly (cathode). The cathode is at a large negative voltage compared with the anode, so the Xenon ions accelerate toward the screen, through the screen with great velocity, and out the back of the ion engine (with a nice blue-green glow), and providing thrust for Dawn.
Some of the electric energy is also used to produce free electrons (mostly from the Xenon ions), which are also emitted from Dawn, to neutralize the charge on the spacecraft. Otherwise, the Xenon ions would simply turn around and end up striking Dawn, and the net thrust would be zero.
In another, related, method of moving spacecraft... electric energy is used to spin a flywheel. If no torque is applied to the spinning wheel, the attitude of the spacecraft remains unchanged. If torque is applied to speed up or slow down the flywheel, then the attitude of the spacecraft is changed. Using 3 such wheels it is possible to point the spacecraft in any direction in 3-dimensions. With a 4th redundant wheel oriented across all 3 axes, any one of the X, Y, or Z wheels may fail and the 4th wheel can "take over" for the failed wheel.
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2007-10-11 05:06:46 · answer #1 · answered by tlbs101 7 · 2⤊ 0⤋
Depends on the probe! Some newer models have ion propulsion.......they have a kind of 'magnet' on the front that scoops up the few particals and debre that naturnal linger in space, then heat/compress them into a small puff of gas that is ejected behind the vehicle! Techically the force exerted by this engine is minute and pathetic, but slowly, the probe does build speed!!!
2007-10-11 04:50:08 · answer #2 · answered by Anonymous · 0⤊ 1⤋
Nothing slows it down, so after the initial push, it doesn't need to keep propelling itself. On earth, when something starts to move, it slows down because of gravity and friction. But in space, there's no friction and no gravity (well, there's never NO gravity, but there's a LOT less). Newton's first law of motion, which will be the first thing they'll teach you in a physics class is
"An object in motion will remain in motion unless acted upon by a net force."
So with barely any friction or gravity acting on a satellite to slow it down, they'll keep moving for forever. The only thing that would stop them is if they ran into something, or got too close to a gravitation field which pulled them in.
2007-10-11 04:47:22 · answer #3 · answered by Eli 6 · 1⤊ 1⤋
some have solar panels (photovoltaic cells) to generate further energy. But if an object in space is moving at a constant speed, in a straight line, a long way from other objects (stars/planets etc) it will carry on at that speed in a straight line because the forces on it are balanced.
2007-10-11 04:49:49 · answer #4 · answered by telstar5035 2 · 0⤊ 0⤋
It's in space. No air - no gravity - nothing to stop it. But it can fire things to change direction.
2007-10-11 04:49:35 · answer #5 · answered by Mike10613 6 · 0⤊ 2⤋
release a gas
2007-10-11 04:47:34 · answer #6 · answered by big bill 3 · 0⤊ 0⤋
maybe it has propellers
it orbits some
no clue
2007-10-11 04:48:03 · answer #7 · answered by Anonymous · 0⤊ 3⤋