US service provider DirecTV is racing to take its satellite out of geostationary orbit due to a battery malfunction that could cause a 'catastrophic' explosion.
The satellite service fears that an explosion could take out other satellites in the geostationary orbit around Earth, 22,200 miles above the equator.
Satellites in the geostationary orbit follow the rotation of Earth so that antennas don’t have to rotate to constantly receive a signal.
DirecTV requested permission from the US Federal Communications Commission to conduct ‘emergency’ operations to de-orbit Spaceway-1.
If these operations are not carried out, Spaceway-1 could explode in a month's time and damage surrounding satellites that transmit TV signals via other providers.
An artist's rendition of a Boeing 702HP satellite similar to DirecTV's Spaceway-1
Companies with spacecraft orbiting the Earth are required to discharge all remaining propellant prior to decommissioning a satellite to reduce the risk of explosion.
However, in a filing to the FCC, AT&T-owned provider DirecTV has asked for a waiver as this can take two to three months.
‘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 the eclipse season,’ the filing says.
‘DirecTV’s emergency operations are in response to the extraordinary and unforeseen anomaly on Spaceway-1 and will reduce the potential for harm to other geostationary satellite operators.’
DirecTV is proposing that Spaceway-1, which was manufactured by Boeing, is sent 300 kilometres above the geostationary orbit into what is known as ‘graveyard orbit’ for disused satellites – or the great orbit in the sky.
The provider is blaming a ‘major anomaly’ that resulted in ‘significant and irreversible thermal damage’ to the batteries on Satellite-1.
The batteries’ cells cannot be guaranteed to withstand the pressures and there is a ‘significant risk the battery cells could burst’.
Satellites like Spaceway-1 follow the Earth's orbit so rooftop antennas held can receive direct-broadcast satellite television
DirecTV terminated the satellite’s payload and is operating the satellite through its solar panels – however the use of battery power will be ‘unavoidable’ when it passes through Earth’s shadow from late February.
Model: Boeing 702
Weight: 13,400 pounds
Launch date: 2005
Operational position: 22,200 miles above the equator at 103.0 degrees west longitude
This means DirecTV has about a month to move Spaceway-1 into graveyard orbit before it potentially explodes – although it is still finalising its de-orbit plan.
‘Spaceway-1 will first need to increase its eastward drift before turning around and completing a near-continuous burn until it reaches its disposal orbit,’ DirecTV said.
‘The sequence will take approximately 21 days, leaving at least seven days for venting operations before the spacecraft is to be decommissioned.’
DirecTV also reminds the FCC that the commission stipulates that it can provide a waiver of its fuel rule ‘for good cause shown’ – as in this particular case as it is in the public interest.
Accepting DirecTV’s request will limit the risk of accidental explosion and potential harm to other geostationary satellite operators, it said.
Spaceway-1 currently shares the orbit with around 400 other satellites, according to Satellite Signals.
Spaceway-1 is a back-up satellite providing Ka-band capacity in Alaska and that no customers were affected by the anomaly, the operator said.
It is now ‘exploring plans’ to replace the back-up capacity lost by the decommissioning of the craft.
DirecTV had recently requested for the 15-year-old Spaceway-1 to have its operational license expanded until 2025.
WHAT IS GEOSTATIONARY ORBIT?
Geostationary orbit is a circular orbit populated by satellites 22,236 miles above the Earth’s equator.
Satellites in the orbit follow the direction of Earth’s location, meaning they can appear at a fixed period in the sky at any time of day.
Communications satellites, for TV, radio, internet and even military communications, are placed in geostationary orbit so that satellite antennas back on Earth don’t have to constantly rotate to pick up signals.
There are currently around 400 satellites currently rotating around the geostationary orbit.
Geostationary orbits were actually proposed by Arthur C. Clarke, the British famous science fiction writer, in 1945.