VASIMR stand for Variable-Specific-Impulse Magnetoplasmadynamic Rocket. It is a type of electric propulsion that is efficient over a large range of specific impulses. This allows specific impulse to be exchanged for thrust. It is a marginal improvement over ion engines or Hall thrusters in terms of thrust for any given power level but will allow much faster transit times once much higher power levels are implemented. The VASIMR is very important in this respect because it is deemed much more scalable to these higher power levels than are most other types of electric propulsion. In the above respects, the VASIMR is qualitatively similar to the Pulsed Inductive Thruster (PIT) from a standpoint of most promising future technologies in electric propulsion.
Currently the only company working on the VASIMR is the Ad Astra Rocket Company, owned and run by its inventor. From the web site:
"Dr. Franklin R. Chang Díaz serves as company President and CEO. Dr. Chang Díaz invented the VASIMR concept and has been working on its development since 1979, starting at The Charles Stark Draper Laboratory in Cambridge Massachusetts and continuing at the MIT Plasma Fusion Center before moving the project to the Johnson Space Center in 1994."
The company has produced a 50 kW engine which it has retired and a 100 kW engine which it is now using for materials testing for its future 200 kW engines.
New Mars Discussions
[[http://peaches.ph.utexas.edu/ifs/ifsreports/977_Arefiev.pdf Theoretical components of the VASIMR plasma propulsion concept]] Alexey V. Arefiev and Boris N. Breizman Institute for Fusion Studies, The University of Texas, Austin, Texas 78712
--Mweiss 17:30, 3 March 2009 (UTC)