PanAmSat's Galaxy V111i communications satellite - an HS 601HP model built by Hughes Space and Communications and launched in 1997 - has experienced problems with its xenon ion propulsion system. This system is used by the spacecraft to help maintain its geostationary orbit position of 95°W .
PanAmSat's controllers are using a back-up chemical propulsion system, but this will run out of propellant in 2002. The HS-702 spacecraft Galaxy 3C, however, is scheduled for launch in 2002 and will take over from Galaxy V111i until a replacement for the spacecraft is ready. The replacement will be funded by an insurance claim for in-orbit failure.
Hughes believes that the xenon ion propulsion problem is isolated to the Galaxy V111i satellite and does not affect other HS-601 and -702 model spacecraft. The Galaxy V111i problem is the latest in a series of malfunctions on HS-601 spacecraft buses, including control processor problems affecting five spacecraft.
Source: Flight International
