The VASIMR technology is quite frankly amazing. The fuel efficiency is amazing, a single engine is expected to be capable of station keeping the ISS while vastly reducing the expenses and beyond Mars VASIMR engines hold a real possibility for manned exploration of the outer solar system.

VASIMR is to space what the Internal Combustion Engine has been to land. Quite literally it only takes minor modifications to the VASIMR design to attain a faster engine or a stronger engine for a variety of tasks.

In the future these engines will be being used for everything from travel between planets, to moving asteroids for mining. They're really quite incredible.