The idea kind of provokes an image of the Caterpillar Drive in “Hunt for Red October”. But, that at least was water which is electrically polarized; and seawater, being heterogeneous is full of stuff an electrical engine can grab onto.
But, I was making a point in another question on Y!A (below link) that I’ve always maintained, that the limiting factor on spacecraft performance is propellant not fuel. And, spacecraft with an air-breathing first stage would harvest free propellant from the air on the first hardest 70 kilometers to climb out of our gravity well.
http://answers.yahoo.com/question/index?qid=20090718160004AAoEecU&r=w#Bc0sBzDrJFm2_oPzWaA_
There was an article I found where this guy was talking about air-breathers and how they only use a tiny fraction of the air, just the oxygen, as an oxidizer (below link). Now I’d counter that’s using it as a fuel; but an air-breather uses 100% of the air that goes into its engine as propellant. (Well I’m not absolutely sure of that. Part of maximizing thrust is making sure that as your burning fuel-air mix exhausts out the engine and slips away it does exert a maximum of force on the engine, which I would expect is hard to do at hypersonic speeds. Then again that problem is no less than the same for rocket engines.)
http://www.newscientist.com/blogs/shortsharpscience/2009/03/rockets-not-air-breathing-plan.html
But, what if you were to instead ionize the air as it comes in and feed it through a high speed electrical engine. Can you ionize air? This wouldn’t be like those at home ionizers. As far as I know those just ionize dust in the air. Would that be enough for propulsion? Could you ionize air quickly and efficiently enough for it to matter?
Would you need to ionize the air? Could an air-breathing electrical engine ride the ionosphere out of our gravity well?
I’m wondering because then you’d be separating the engineering problems of the powerplant and propulsion. And, you’d have the possibility for an ion rocket that operates with variably high exhaust velocities in the freefall between planets (like a VASIMR), but which also can provide the thrust to boost itself out of a gravity well.
http://en.wikipedia.org/wiki/Variable_specific_impulse_magnetoplasma_rocket
I forgot what I’ve basically written about here is a ramscoop engine. But, all the ideas I’ve ever read in science fiction for ramscoops was for a rocket that climbs up to sublight speed using cosmic wind. What I’m writing about is a ramscoop that use solar wind, the ionosphere, or even raw atmospheric air as its propellant.
http://en.wikipedia.org/wiki/Ramscoop
I just did a quick search for “electric thrust” on youtube. (I remembered the Mythbusters had this electrical engine, which was supposed to use antigravity or whatever, but was really a more real physics propulsion at work. I was thinking if that was electrically driven and its propellant was the air, and not say the table underneath it, that might work as an example.)
The search results I got were for electric motor driven ducted fans, which I guess is one way of doing it and would satisfy some of my criteria. However, I’m not aware that scaled up EDFs work all that well. And, no turbine is going to operate well as a launch option, first stage or no.
Woot! I answered my own question. I looked up “antigravity” plus “Mythbusters” and found a video that briefly talked about the “antigravity lifter” which uses the “Biefeld–Brown effect”.
http://en.wikipedia.org/wiki/Biefeld%E2%80%93Brown_effect
Which led to…
http://en.wikipedia.org/wiki/Ionocraft#How_it_works
Which led to…
http://en.wikipedia.org/wiki/EHD_thrusters
Which is almost exactly what I’ve been writing about. Pity that it seems others have already pretty well looked into, though it doesn’t really say how well it’s thought they’d work. It also says they can’t operate in a vacuum; but surely that’s just a matter of closing the intake to form an ion chamber, and feeding in propellant to transform it from an ion air-breather to an ion rocket. Right?
Was that before or after the cuprate-perovskite ceramic breakthrough in superconducters in 1986?
http://en.wikipedia.org/wiki/Superconductors
http://en.wikipedia.org/wiki/File:CERN-cables-p1030764.jpg
