The Boeing-built Spaceway 1 spacecraft suffered an anomaly in December that caused “significant and irreversible” thermal damage to its batteries. The spacecraft’s owner DirecTV has informed the Federal Communications Commission (FCC) that it will be retiring the satellite from geostationary Earth orbit and placing it into a graveyard orbit some 300 km above GEO. The spacecraft was already three years beyond its 12-year design life following its launch by a Zenit 3-SL (Sea Launch) in 2005. The Earth spin benefit and lack of need to withdraw inclination due to launch from a converted oil rig at the equator saved enough fuel to allow prolonged use of the satellite.
The decision to retire the spacecraft has been made as the eclipse season is approaching when it would fall into shadow for certain periods. For control to be maintained, a fully working battery system is required. One further complication is a concern that the battery might explode. As such, DirecTV has asked the FCC for permission to reach the graveyard orbit before a full passivation/venting of no-longer-required propellants has taken place.
Artist’s impression of Spaceway satelite. Courtesy: Boeing
