Hollow Cathode Life Issues

L-3 Communications ETI (formerly Boeing Electron Dynamics Division and, prior to that, a division of Hughes Space and Communications) is a company with significant background in both cathodes (used in space traveling wave tubes) and electric propulsion. L-3 ETI has been responsible for developing a cathode life model as presented in R. T. Longo (2003) that is recognized throughout the industry and has also been a key enabler in the development and manufacture of gridded ion thrusters. Testing of the 25 cm xenon ion propulsion system (XIPS) has demonstrated 2 potential ignition issues associated with the hollow cathode assembly: delayed ignition due to barium depletion and heater failure. In its role in satellite station-keeping, the XIPS engine is ignited daily over a 15 year mission so that a detailed understanding of the ignition process is important in evaluating its life. The heater used to ignite the XIPS cathode assembly represents a single point failure so that dealing with potential failure mechanisms is critical in ensuring mission life