Re: Plasma Rocket!
Yes, this report is about the good old VASIMR engine, which has been in the news for a few years now
http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magnetoplasma_Rocket
http://www.google.com/search?q=vasimr
Like most engines of its type, the thrust is low, but the "gas mileage" (specific impulse) is fantastic. It is no good for take off or landing, but it is great for traveling between planets.
Also, unlike almost all other engines, it can "shift gears." That is, it can increase the thrust at the expense of gas mileage, and vice versa.