VASIMR plasma thruster tested

http://space.newscientist.com/article/dn12064-plasma-rocket-breaks-endurance-record.html

A VASIMR (Variable Specific-Impulse Magnetoplasma Rocket) plasma thruster would permit LEO cargoes dropped from the ribbon to go into a circular orbit in a reasonable amount of time.  The thruster would permit manned capsules to fly up to GEO permitting return to the Earth via the Space Elevator.  Fast return trips from the Moon and Mars become possible.

The 10 MW of photovoltaic panels (or solar thermal power) needed is close to the power needed by the lifters so they could share solar and cooling panels.  A successful test means that the technology is under active development.  This is a company that is worth watching.

http://www.adastrarocket.com

Maybe quick trips to far off places.  It's specific impulse is fantastic like any electric rocket but it does not have the thrust required to make short trips like to the moon.  It just doesn't accelerate quick enough like a chemical rocket does.