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For those of you who are unclear on why the VASMIR system is so cool, allow me to give you a brief bit of background. Practically every propulsion method developed to date falls into one of two categories:

1. High thrust, low efficiency
2. Low thrust, high efficiency

Generally how it works is that the more power you get out of engines, the less energy you extract from the fuel. This is the case of chemical fuels like Liquid Hydrogen/Oxygen or Kerosine. These fuels provide the massive amounts of thrust necessary to get off the ground, but they burn through their fuel very quickly. Interestingly, LHOx is more efficient than Kerosine, but it's also harder to get as much raw thrust out of it. That's one of the reasons why Kerosine was the heavy lifter during the space race with the LHOx engines reserved for in-space stages.

On the other side of the coin, you have engines like Ion propulsion. These engines are able to inject incredible amounts of energy into tiny amounts of fuel, thus making them extremely fuel efficient. The only problem is that the amount of thrust is very low. Most of the ion engines that have operated to date produce thrust that matches the weight of a sheet of paper. Definitely not enough for liftoff, but perfect for extended missions in space where constant low thrust provides more velocity over time than the chemical engines which fire once, then coast the rest of the way.

The problem with both types of engines is that neither one gets spacecraft to their destination all that fast. Chemical rockets have the thrust to do it, but you couldn't feasibly build a chemical rocket with enough fuel to get you to another planet in a reasonable amount of time. A nuclear pulse propulsion craft could feasibly get fairly close, but it would just have more power in the intial thrust rather than providing a constant, high power thrust. (Obviously these have been discounted over the difficulties of building a large enough craft without using a nuclear ground launch. Nuclear ground launches are a no-no under current test-ban treaties.)

This is where VASMIR comes in. These engines are incredibly efficient. The specific impulse (measurement of efficiency) is between 3,000-30,000 seconds depending on the configuration and current thrust levels of the engine. This compares favorably with the ~450 seconds of shuttle engines and 3,000-10,000 seconds of Ion thrusters. Meanwhile, the thrust of Ion engines ranges from 90-3,000 mN while the thrust of VASMIR is expected to be ~5000 mN of thrust when tested at 200 kW of power.

What this means is that we may be able to build spacecraft where a trip from LEO to the moon is a daily affair and a trip from LEO to Mars takes only a few months (or less!) vs. the current flight time of nearly a year. The better these engines get (and the more we can put on a craft), the faster those flight times will get!

Superconducting Plasma Rocket Engine?

Sounds like it oughta be able to make at least Warp 3.

Superconducting: check
Plasma: check
Rocket: check
Linux:

Three for four isn't bad.

In Yiddish (the Jewish-German creole of Eastern Europe), VASIMR means "woe is me".

I know, probably o/t.

It doesn't matter too much how efficient a power source is, as long as the fuel is plentiful. For instance, if you have a REAL LOT of petrochemicals it doesn't really matter how much you have to use to get to mars, etc. BUT more important is how DENSE the energy source is...i.e, how much more of the fuel does it take to move the fuel that is going to be used later on. This gets to be a BIG PROBLEM with chemical fuels, as even at their best they are not very DENSE. Of course, efficiency helps. But say, for a moment, that you have a nice large nuclear power plant on earth...you could probably use all that heat to either directly or indirectly (though electricity) create some high-density chemical fuels...but there's a limit to how much power a chemical fuel can provide. We need NUCLEAR FUEL, be it fission or fusion, or even better ANTIMATTER fuel. While some people claim that nuclear fuel is too dangerous to use on earth, I disagree. But I do think that antimatter is too dangerous to be used anywhere in the vicinity of important and/or massive objects (can't have the earth or space station pummeled by shrapnel in the case of an antimatter explosion, can we? And remember, there's no air friction to slow this shrapnel down). So, the best advice is to use fission, or hopefully fusion once technology gives up on the silly Tokamak idea, to leave earth's gravity well and move far enough out of the plane to be safe, and then use antimatter to the long haul. What, you say antimatter is too expensive? That's only because you've picked the wrong places to manufacture it. Production using solar power in CLOSE SOLAR ORBIT, in a thousand factories, should make antimatter cheap enough. You just have to go fetch it from close-solar orbits, which can be robotically done using the antimatter as fuel itself! The factories themselves can be replicaed using easily available materials from the moon or asteroids, and then replicated in close solar orbit using the vast energy resouces of the sun.

So to sum up, the problem isn't the amount of energy required, but the location of that energy. Move our energy conversion devices closer to the source, and we'll have plnety of consumable energy, even if it has to go through several intermediate storage mechanisms to become safe and easily accessible.

And yes, I've said this in other places, over time. I just hope that I get through to someone who is charged with long-term planning for space exploration.