Microsatellite Plasma Propulsion

The development of launch-light, kilogram-class microspacecraft has gone well owing to new MEMS (microelectromechanical systems) technology, with one notable exception: matching miniature thrusters, the mini-rockets that steer the orientation of the craft and make orbital adjustments.

John Foster, a researcher at the NASA Glenn Research Center in Cleveland, has now built a tiny rocket that develops thrust by accelerating xenon ions from a plasma generated in millimeter-sized cavities. The device accomplishes this on a millimeter scale without the need for exotic permanent magnets or bulky electromagnets.

The device is extremely fuel efficient; 88% of the fuel is successfully turned into ions. The new compact accelerator produces a beam of ions in the 50-200 eV range and so, besides maneuvering microsatellites in orbit, the device might be useful for doing surface chemistry and thin film production. (John Foster, Review of Scientific Instruments, May 2002, john.foster@grc.nasa.gov; see picture of test firing at Physics News Graphics.)