An artist's concept of Galaxy 3R. Photo: Boeing Satellite Systems

PanAmSat Corporation announced Monday that the Galaxy 3R domestic satellite experienced the apparent failure of its primary spacecraft control processor (SCP), which caused the satellite to automatically switch control to its back-up SCP. Normal satellite operations were restored through the use of the back-up SCP. PanAmSat and the satellite manufacturer, Boeing Satellite Systems Inc., are continuing to investigate the apparent failure.

A Boeing 601 spacecraft launched in 1995, Galaxy 3R experienced the failure of its primary SCP at 2:40 p.m. Eastern time on Saturday causing a temporary outage of some C-band and Ku-band transponders. Normal operations were restored to the satellite within two hours, during which time some customers experienced brief interruptions of service.

In response to satellite technical issues, PanAmSat implemented a comprehensive satellite expansion and restoration plan in 1998 that includes the launch of four new Galaxy spacecraft as replacements for satellites that could suffer SCP failures. As part of this plan, PanAmSat is set to launch the fourth satellite in the series, Galaxy 3C, during the third quarter of this year to serve as the replacement for Galaxy 3R at 95 degrees west longitude.

Boeing has previously concluded that SCPs on Boeing 601 spacecraft launched prior to August 1997 contain tin-plated relay switches that can experience electrical shorts when several factors are concurrently present. The PAS-4 Indian Ocean Region satellite experienced the failure of its primary SCP in November 1998 and continues to provide normal service on its backup SCP. PanAmSat plans to launch PAS-10 in May to serve as the replacement for PAS-4 at 68.5 degrees east longitude.

"PanAmSat took immediate and successful action to assure the highest level of service for all our Galaxy 3R customers," said Robert A. Bednarek, PanAmSat's executive vice president and chief technology officer. "In addition, our on-going satellite expansion and restoration effort has afforded us the capability to offer unparalleled backup and redundancy for our customers."