Space coilgun = free travel

[Cinon]

Hi, can anyone make a part or mod that gives us a giant space coilgun? I want to be able to accelerate or decelerate other spacecraft, using only electricity!

The utility of such a thing would be endless and it would give the ability to go around the solar system using no fuel at all!

Here is an example: imagine that you had one big coilgun attached to a space station orbiting kerbin and one orbiting mun.

From kerbin, you can propel a light spacecraft and put it into a transfer trajectory to the moon. The coilgun will slow down of course, but since it's much more massive than the spacecraft being propelled, it's speed will not change much, meaning it will remain in orbit.

Now the spacecraft meets with the coilgun that is orbiting the moon and the coilgun decelerates it, taking all of it's energy. The spacecraft will now fall vertically towards the moon and will only need fuel for the landing. The coilgun will of course gain speed, but since it's massive, it will remain in orbit around the moon.

Now when the spacecraft wants to return to kerbin, it needs only enough fuel to reach the periapsis of the coilgun, after which the coilgun gives back the original kinetic energy and the spacecraft is now on an escape trajectory. The coilgun returns to it's original orbit due to the transfer of energy.

The spacecraft meets with the coilgun orbiting kerbin and then after a violent exchange of energy, their speeds will be the same and back to the starting orbit.

If one puts such a coilgun on another planet, it will be possible to go between that planet and kerbin, for free!

I imagine the coilgun to be a very long tube with electromagnets attached radially all over it.

Of course the only problem will be very precise maneuvering, penalty the complete destruction of both the coilgun and the spacecraft

Btw let's not forget that it's possible to steal energy from the moon by doing slingshots around it and then store the energy into a space station (until the moon starts to enter kerbin's atmosphere...)

Edited February 3, 2015 by Cinon

[Thomas988]

Hmmmm...interesting idea. I think it would be fun if you installed a lot of planet packs including distant solar systems.

Also, this should be in the General Add-on Affairs forum.

[Vanamonde]

This affair about add-ons has been moved to Add-on Affairs.

[Randazzo]

So... you want to fire a vessel out of a railgun... into the barrel of another railgun..while both are orbiting celestial bodies?

Holy Jebediah, batman.

[SRV Ron]

Would require massive amounts of electrical energy to use. As far as the gun itself remaining in orbit, it would accumulate enough energy to kick it out of orbit. Example, just the effects of gravity from the moon on the Earth's oceans are causing the day to get slowly longer as well as causing the moon to speed up in orbit causing it to move further away by a couple of inches every year.

Still, have fun with the concept.

[RainDreamer]

You are looking for this thing: Netherdyne Mass Driver Mod

It is a mod in active development, and thus may be buggy and broken. You have been warned.

[Cinon]

You are looking for this thing: Netherdyne Mass Driver Mod

It is a mod in active development, and thus may be buggy and broken. You have been warned.

Perfect! Thank you

[Agumander]

Perhaps a mass-driver station could have big engines on it for station-keeping? It would then require periodic refueling missions, but then that fuel wouldn't need to be carried by every craft that wants to make the voyage.