slingshot in space?

Question

From my limited uderstanding, we can use magnetism to move trains really fast here on earth.
what if we took that train, put it in space, and instead of it riding on a rail on the base,
the train is enclosed in a tube (like in a particle accelerator) made of electromagnets
placed together to form rings with the train pulled from the front and repulsed from the rear
accelerating in a circle and with the magnets on the ring redistributing the the force of the
magnets on the train as it turns, compensating for the trains outward motion, and then shot out through a
linear section of the tube. the question is, by eliminating gravity and friction from air,
how fast is fast and if this is a plausible concept, could we use this as a way to deliver
equipment and rations in space.
If anyone answers, i have another question relating to this.

Answer 1

Accelerating in a circle is not a good idea, as the centrifugal force of something as heavy as a train would quickly overcome even the strongest magnetic field. It's better to accelerate in a straight line, which is called a railgun.

While a railgun is theoretically possible, the speeds you can attain are fairly modest by spaceflight standards. The principal equations you need for calculation are these:

1.
a = v / t
a is acceleration, v is velocity, t is time. In metric units, an acceleration of 1g (1 x the force of gravity) is 9.8 m/sec^2

2.
d = 1/2 a t^2
d is distance (in meters)

3.
e = 1/2 m v^2
e is energy (in Newton-meters)

4.
p = e / t
p is power in Watts

When you do the math, start by assuming some reasonable value for your mass, the length of your railgun, and the maximum acceleration your astronauts can stand on launch. You find that in order to get up to spaceflight speed, you need (1) a rail tens or hundreds of miles long, (2) an acceleration several times that of gravity, and (3) the power requirement of a large dedicated powerplant. Not too practical!

Answer 2

I agree with jared. What you are describing is a railgun. This is a gun that uses magnetism to propel an item. In the vacuum of space, there is little or no friction so it is possible to get really close to the speed of light. Now if you add the true slingshot manuever, you can really get close to the speed of light, but that would require that your object slingshots around massive gravity fields.

Answer 3

The slingshot effect is best explained as part of the vector nature of velocity. When falling toward another object that other object is also moving. The relative speed between the two objects is about the same in magnitude when the objects are approaching and are a particular distance apart and again when the objects are separating and have again reached that distance of separation. If the smaller object approaches the larger and then leaves the larger object essentially going the same direction that the larger is traveling then since the relative speeds are going to be about the same upon leaving, The smaller object will have added to it's own speed, the speed of the larger object.

Answer 4

The main problem with what you are describing boils down to Newtons Law.. Every action has an equal and opposite reaction.

Even though you are accellerating your train in a circle, which might lead you to think things are balanced, consider in the end your vehicle will leave the launcher at some speed.. There for there is a relative acceleration between the launcher and the vehicle. So in addition to accelerating your train, you have also accelerated your launch structure! (Now the launch structure is likely much more massive than your vehicle, so its acceleration will be less - but still took the same force). In order to keep your launch structure in a stable orbit, you would have to counteract the acceleration with rockets... And because equal and opposite reactions rule, the amount of rocket power you would need is exactly the same that you could have strapped right on your train to accelerate it to the same speed at which it left your station..

Answer 5

this in not a good way of delivering rations in space.

Why would you want a fixed tube in space when a shuttle is so much more efficient? Tubes will cost lots of money and are pointless are the position and direction is fixed and things in space tend to move about, if you hadn't noticed:)

You question is barely understandable. Try and use more than one sentence next time.

Answer 6

I think you are describing a railgun.

There are theories about using railgun type technology to send objects into space or for accelerating from one system to another, but the cost and the physics behind them are so great that it will probably not be a viable option.

http://en.wikipedia.org/wiki/Railgun