Is it posible that the magnetic fields of celestial bodies, such as the Sun and the Earth, could be used for spacecraft propulsion? If so, what type of drive would be needed to harness it? Finally, if magnetic fields can be harnessed and used for spacecraft propulsion, could a craft be accelerated near the spead of light?
I would say the main problem with that idea is that magnetic feilds are generally weaker as you move away from the source... I wouldn't imagine that the electromagnetic field of the sun or earth for instance would be enough to result in any significant mechanical force once you converted it to such. Small forces are sometimes fine for propulsion as long as you have access to them for a long time... like that theoretical propulsion system "solar sail" uses photons.. very small force but available for very long time... can approach speed of light eventually (maybe somewhat quickly, I'm not really versed in it). I would imagine that given my initial statement, you would have a hard time designing a usefull electromagnetic propulsion system for traversing between celestial bodies and such. I would however think that one might be able to do so for orbit type propulsion, but I would say that there's probably no feasible application for such as of yet or it would have been done. Hell as far as I know it's already been done and scrapped as a bad idea. oh, this question is really more applicable to physics and math.
If you could figure out a way to increase their power in a limited radius, say, a ship's engine, then maybe you could slingshot your way around the universe. Think of it as sort of a scifi jet engine. A little dark matter here, some anti matter there, mix it in with gravity and you've got lightspeed baby... the limits of my scientific knowledge are showing here, I hope this is clear
A space craft under a magnetic field could produce thrust via a very long superconducting rail that would pulse its own magnetic field like a liner electric motor, This in turn would grab onto surrounding magnetic fields and provide acceleration. Interstellar and stellar magnetic fields are too weak to provide any reasonable thrust. Even under Earth or Jupiter’s magnetosphere the weight of the magnetic rail and powersouce would be very great just to provide very minor few millinewtons of thrust. Magnetic propulsion could be achieve much more easily by not a grabbing magnetosphere but solar winds instead. By charging a large super conductive ring a ship can produce a magnetic field large enough to deflect solar wind and produce viable propulsion. Though a magnetic solar sail could only travel away from the sun. By adding charged particles to the artificial magnetosphere the size and weight of the propulsion system can be drop drastic… but charged particles would be lost to the wind and this propulsion system would have a specific impulse value of about 10,000-30,000 compared to Ion propulsion of 4,500-10,000 http://www.geophys.washington.edu/Space/SpaceModel/M2P2/ http://www.islandone.org/APC/ This one I added in for kicks: http://www.howstuffworks.com/electromagnetic-propulsion1.htm
"A magnetic solar sail could only travel away from the sun. " But as it did so the size of the magnetic bubble would increase due to less solar pressure? twice as far, four times the collecting power?
I think there would be a limit to how large the field can get... Not that I’m objecting just there is a limit to how far away a solar sail propelled ship could get. Read those links they should answer all questions. Also it looks like I was wrong about Magnetic propulsion! It is feasible to run in Earth and Jupiter space! It does not require superconductivity or large amounts of power! Here are the links:std.msfc.nasa.gov/news/Tether_propulsion.pdf http://www.space.com/businesstechnology/technology/space_tether_020306-1.html Bottom of this one: http://www.islandone.org/APC/Tethers/01.html
Why stop with magnetic fields? Why not use matter and antimatter? That would create one of two scenarios: blowing up you and 2,000 of your closest friends, or an effective means of unstable, yet incredible high velocity propulsion. Hehehe.Please Register or Log in to view the hidden image!
How to make enough anti-matter is the problem. At modern production capabilities it would take a billion years to make 1 pound of anti-hydrogen! Stick with the magnetic propulsion debate on this page please.
If you watch the science channel enough, you'll see that there are some hardcore physics geeks that have devised propulsion systems based on antimatter... and a bunch of other junk. I love the science channel, but my wife seems to leave the room a lot faster when I have it on. I don't get it. Please Register or Log in to view the hidden image!
Thanks My orginial plan was to use an array of liquid Helium-cooled superconducting electromagnets, but the "ring" thing works too. You could potentially make the "ring" in segments and use miniature movements of those segments to angle the ship or manuver in flight. One problem that I have though of, though, is that as you approach the speed of light, time slows down (duh). So, in order to get anywhere with any amount of accuracy, you would need a computer (a Cray?) to cruch all of the variables and determine a course, compensating for things like I said above, before you started moving. Final problem, stopping...
