VASIMR Magnetic Plasma Rocket Could Send Humans To Mars In Just 39 Days

I've said before, here on CR4, that a manned trip to Mars is a non-starter until a propulsion system is developed that can get men there in weeks, not months. The risk of equipment failure is too large, and the risk of radiation exposure is too great, to risk sending humans to Mars in a mission that takes months.

This engine has potential, but I think a think a system of in-flight refueling will also be needed. No matter how efficient the engine is, it still needs mass to squirt out the nozzle to get sufficient thrust, and a single rocket that carries all the propellant to get to Mars will be unrealistically large. A system for in-flight refueling will allow for a smaller manned rocket yet still provide the fuel for the Mars trip.

Probable complexity nightmare.

accelerated plasma rockets with particle velocities in the millions of degrees compared to thousands of degrees for chemical rockets are (1) intrinsically safer (no particular pressure explosion hazards), and (2) require about 1/1000th the amount of fuel to produce the same thrust integral, or maybe 1/1000000th, since

K.E. = 1/2 m v² and this would seem to indicate that specific impulse is totally proportional to the kinetic energy of the propellant.

Is = 1/2 m V² (or not), since actual Isp = V/g (g is earth's gravitation constant). It is most likely the specific impulse is 1000X with plasma engine (VASIMR) than it could ever be with same mass units of chemical engine. I like those odd, but also the spacecraft terminal velocity would be vastly higher than with the chemical rocket.