1. 1Sengupta, A., Brophy, J. R., and Goodfellow, K. D. “Status of the Extended Life Test of the Deep Space 1 Flight Spare Ion Engine after 30,352 Hours of Operation,” 39th Joint Propulsion Conference, 2003.
2. 2Sengupta, A. “Destructive Physical Analysis of Hollow Cathodes from the Deep Space 1 Flight Spare Ion Engine 30,000 Hr Life Test,” 29th International Electric Propulsion Conference, Princeton, New Jersey, 2005.
3. 3Goebel, D. M., Katz, I., Polk, J. E., Mikellides, I. G., Jameson, K. K., and Liu, T. “Extending Hollow Cathode Life for Electric Propulsion in Long-Term Missions,” AIAA Space 2004 Conference, 2004, pp.1-12.
4. 4Sarver-Verhey, T. R. “Scenario for Hollow Cathode End-of-Life,” 26th International Electric Propulsion Conference, Kitakyushu, Japan, 1999, pp.703-713.
5. 5Hofer, R. R., Randolph, T. M., Oh, D. Y., Snyder, J. S., and de Grys, K. H. “Evaluation of a 4.5 kW Commercial Hall Thruster System for NASA Science Missions,” 42nd Joint Propulsion Conference, Sacramento, California, 2006.