ELECTRIC PROPULSION ACTIVITIES IN U.S. INDUSTRIES

Use of Electric Propulsion (EP) on commercial telecommunications satellites continued to grow in the United States during the past year -and-a- half, even with flat overall demand for satellites. Worldwide launches included more spacecraft with Xenon Ion Propulsion Systems (XIPS) and Hall Effect Thrusters (HETs) than electro -thermal systems, such as arcjets and resisto -jets. There were six new geosynchronous satellites with XIPS launched by Boeing Satellite Systems (BSS). In the same period of time, NPO -PM, in Russia, launched another EXPRESS satellite with HET propulsion. Currently there ar e 25 satellites in orbit with HET systems for EP stationkeeping, and 19 satellites in orbit with XIPS. Several new spacecraft were also flown with arcjets and some with resisto -jets. We are seeing increased interest in using EP for orbit raising applicati ons as well as for stationkeeping. Thrusters with increased power levels are being developed to meet this need. At the same time there is a healthy activity in development of Pulsed Plasma Thrusters (PPT), and micro -propulsion systems for smaller spacecr aft.