The Variable Specific Impulse Magnetoplasma Rocket (VASIMR) is an electromagnetic thruster for spacecraft propulsion. It uses radio waves to ionize and heat a propellant. Then a magnetic field accelerates the resulting plasma to generate thrust (plasma propulsion engine). It is one of several types of spacecraft electric propulsion systems.
A nuclear reactor has a very large amount of energy per unit mass; a reactor core has the highest energy density of any useful energy source on earth. This high energy density and scalability make nuclear reactors an ideal power source in space. A nuclear-electric powered spacecraft could dramatically shorten human transit times between planets and propel robotic cargo missions with a very large payload. Trip times and payload mass are major limitations of conventional and nuclear thermal rockets because of their inherently low specific impulse (less than 1000 seconds). A VASIMR® propelled, nuclear-electric powered spacecraft promises to make fast human missions a reality.…