Hughes Satellite Failures Continue To Plague New Owner News from E-InSiteEarlier today, PanAmSat Corporation announced that its Galaxy IIIR satellite hadapparently experienced a failure of its primary spacecraft control processor (SCP) overthe weekend, which caused the satellite to automatically switch control to its back-upSCP. Normal satellite operations were subsequently restored through the use of the back-upSCP. PanAmSat and the satellite manufacturer, Boeing Satellite Systems Inc., arecontinuing to investigate the apparent failure.
'PanAmSat took immediate and successful action to assure the highest level of servicefor all our Galaxy IIIR customers,' said Robert A. Bednarek, PanAmSat's executive vicepresident and chief technology officer in a prepared statement. 'In addition, our on-goingsatellite expansion and restoration effort has afforded us the capability to offerunparalleled backup and redundancy for our customers.'
Launched in December of 1995, Galaxy IIIR experienced the failure of its primary SCP at2:40 p.m. Eastern time on April 21 causing a temporary outage of some C-band and Ku-bandtransponder capacity. However, normal operations were restored to the satellite within twohours.
The Boeing Company acquired satellite manufacturer Hughes Space and Communications lastyear in an all-cash transaction valued at $3.75 billion. As a result, Boeing has inheritedwhat seems to be an intractable problem involving certain satellite platforms using theHS-601 spacecraft bus.
Last autumn, PanAmSat Corporation announced that its Galaxy VII backup satellite hadceased transmissions due to the failure of the SCP system responsible for controlling thespacecraft's orientation in space. The total loss of the 3,700-lb. spacecraft was anuncanny repeat of the catastrophic failure of Mexico's Solidaridad satellite thatoccurred just a few weeks earlier.
In June of 1997, the backup SCP on PanAmSat's Galaxy IV satellite experienced ananomaly. Then in May of 1998, Galaxy IV was declared a catastrophic loss when both itsprimary and backup SCPs simultaneously failed. Similar SCP anomalies involving Mexico'sSolidaridad satellite, PanAmSat's PAS-4 spacecraft and DirecTV's DBS-1 satelliteTV platform have also occurred during 1998, prompting Hughes to launch an officialinquiry.
Hughes Space and Communications subsequently concluded that the SCPs carried by allHS-601 spacecraft launched prior to August 1997 contain tin-plated relay switches that cancan experience electrical shorts when several factors are concurrently present. Companyinvestigators said that the most probable cause had been traced to a tin-plated latchingrelay that serves as an on/off switch within the SCP. Under certain combined conditions, atiny, crystalline structure less than the width of a human hair was found to grow andbridge a relay terminal to its case, causing an electrical short.
At the conclusion of its 1998 investigation, Hughes maintained that anothercatastrophic failure similar to the one that had disabled Galaxy IV was not expected tohappen.
'While our investigation cannot rule out the possibility that another currentlyoperating SCP could fail,' said Michael Smith, chairman and chief executive officer ofHughes Electronics, 'the probability of both SCPs failing on one in-orbit HS 601 satelliteis very low.'
However, subsequent events have since proven Smith's statement to havebeen unreasonably optimistic.
PanAmSat currently operates three Boeing-601 satellites other than Galaxy IIIRthat incorporate the same faulty relay design. One of these spacecraft, the PAS-4Indian Ocean Region satellite, experienced the failure of its primary SCP back in November1998 but continues to provide service through the use of its backup SCP. PanAmSat,however, is set to launch a new PAS-10 satellite this May that will serve as thereplacement for PAS-4 at 68.5 degrees east longitude. The two other affected spacecraftare presently functioning on their primary SCPs.
The Boeing-601 platform remains the world's most popular satellite flight model. Overforty of these three-axis stabilized platforms are now in orbit, including over a dozenhigh-performance flight models. These satellites provide telecommunication services onbehalf of satellite operators based in Australia, Canada, Hong Kong, Indonesia, Japan,Luxembourg, Mexico, the United Kingdom, and the United States.
isHyperActive's affliated US site.