Professor Umran S. Inan

Winter 1997-98

Date: Wednesday, March 11, 1998

Time: 4:15 PM Refreshments at 4:00

Location: Gesb 124 (Green Earth Sciences Bldg.)

Applications of Plasmas in Satellite Propulsion

Prof. Mark A. Cappelli

Mechanical Engineering Department

Stanford University


Plasmas are now widely used in satellite propulsion applications requiring low-thrust and high specific impulses. An introduction to the various types of plasma sources and acceleration mechanisms will be given, along with a description of the types of plasma thrusters that are in stages of development. In our laboratory at Stanford, the focus has been to improve our understanding of the physics within two vastly different thruster types- electrothermal and electrostatic plasma thrusters. In both cases, our contributions have been in the development and application of advanced diagnostics which permit the interrogation of the plasma stream with minimal invasiveness. Various laser-based techniques, such as laser-induced fluorescence, are found to be particularly useful in the characterization of a number of plasma properties. While providing us with the necessary properties for understanding the basic thruster acceleration mechanisms, these measurements have also been used to validate complex computer simulations of overall thruster performance.