DirecTV fears explosion risk from satellite with damaged battery
WASHINGTON — DirecTV is racing to move its Spaceway-1 satellite out of the geostationary arc after the 15-year-old satellite suffered a crippling battery malfunction that the company fears could cause it to explode.
DirecTV told the U.S. Federal Communications Commission that it does not have time to deplete the remaining fuel on Spaceway-1 before disposing of it by boosting it 300 kilometers above the geostationary arc, a region home to most of the world’s large communications satellites.
Spaceway-1 is a Boeing-built High Power 702 model satellite that was designed to last 12 years. Launched in 2005 on a Sea Launch Zenit 3SL rocket, the 6,080-kilogram satellite originally provided high-definition television direct broadcasting services from its orbital slot at 102.8 degrees west longitude. More recently, Spaceway-1 was being used to backup Ka-band capacity over Alaska.
In December, an unexplained anomaly caused “significant and irreversible thermal damage” to Spaceway-1’s batteries, DirecTV said in a filing dated Jan. 19. Boeing, the filing says, concluded that the batteries are at high risk of bursting if recharged, since the damaged cells can’t be isolated.
DirecTV shut off Spaceway-1’s Ka-band payload, and is operating the satellite using power generated directly from its solar panels. But the satellite will pass through Earth’s shadow in late February, at which point battery usage becomes “unavoidable,” according to the company.
“The risk of a catastrophic battery failure makes it urgent that Spaceway-1 be fully de-orbited and decommissioned prior to the February 25th start of eclipse season,” DirecTV said.
Barring technical failures, the FCC requires licensed satellite operators to vent onboard propellant before moving satellites into the graveyard orbit. DirecTV told the FCC it could deplete no more than “a nominal portion of the approximately 73 kg of bipropellant remaining” on the satellite.
Venting fuel is a safety measure meant to reduce the risk of a decommissioned satellite exploding. While similar satellites have needed two to three months to vent their remaining fuel, DirecTV has only one month to passivate Spaceway-1 the best it can while moving it out of the geostationary arc.
Prior to the battery issue, DirecTV had estimated Spaceway-1 had enough onboard fuel to stay in service until 2025. The company said its priority now is to decommission the satellite prior to Feb. 25 “to limit the risk of an accidental explosion.”
DirectTV said that since Spaceway-1 was a backup satellite, no customers were affected by its failure. Still, the company is evaluating what other spacecraft it could relocate to make up for the loss of backup capacity.