Solenoid 'Launch Gun' in Space

[Pat Says]

Hi, it has been a very long time since I last posted on this forum but I recently thought of an idea and thought this would be the best place to pitch it and see what everyone thinks.

 

I got my inspiration from reading about Vacutrains. I was trying to think of ways to improve on it or to make it faster when it dawned on me that there is one place where you never have to worry about evacuating the environment and that was space. I then got a funny picture in my head of a giant track that went from Earth's orbit to the moon. Obviously that wouldn't work but it lead me to another idea. What if the same concept of a gauss gun or rail gun was used in space.

 

Anyways, here is what I am picturing:

A very big circular electromagnet that sits in orbit storing solar energy in very big capacitors until it is ready to be used. Then a ship needing a boost to say Mars or beyond pulls up in front of this thing. Then the circular electromagnet is turned on using a high burst of energy from the capacitors and pulls the ship through it and launches it on to its destination. To get an added boost I was thinking that maybe an asteroid or anything with a significant amount of mass could be attached to the 'gun.'

 

I also came up with some variations on the concept like something similar to an ion engine where the two objects are initially attracted and then once the ship passes a threshold they would repel each other. Another idea I had was to use multiple donut shaped electromagnets that would continuously increase the acceleration as the ship travels through the 'barrel.' Additionally, after the ship is launched it could deploy solar sails but that's another story.

 

So, what do you guys think? Is it plausible/practical? Thanks for considering my idea.

[Rocket Man]

it would work but there are a few problems with it.

for the solenoid to work, you need the ship to have a decent amount of iron or other ferrous metal in it. now that's all well and good but on a space borne craft, mass is critical. most space craft are made mostly of aluminium or exotic metals to cut down on launch weight.

 

a solenoid is also not likely to be entirely efficient, you'll have all sorts of inductive heating problems everywhere trying to fire up that much of a magnetic feild.

 

nasa has come out with a relatively new approach to satellite insertion, perviously they either had to go to the satellite's orbital or mount a nice big rocket on the satellite, but now they've decided that a tether between the satellite and the shuttle can be used as a sling. you spin the whole shuttle and the satellite accelerates in a circular fassion on the end of a very long cable. then they simply let go and do a bit of their own course correction.

 

a magnetic approach is plausible but a cable is more practical.