The VASIMR (Variable Specific Impulse Magnetoplasma Rocket) has now been tested at 200 KW power and has worked as planned...
The rocket is a leap forward in technology - prior to this particular design, spacecraft were required to take chemical propellants with them... The Plasma rocket uses an electric source that ionizes hydrogen (which is very plentiful throughout the universe) and superheats it to plasma, which can be used as a propellant...
This will provide long duration spaceflight capabilities that have never been available before... A spacecraft using the Plasma drive is scheduled for 2013...