On Friday, August 22, two European Space Agency Galileo satellites were injected into improper orbits shortly after their launch from French Guiana. Since then, the ESA has been actively investigating the situation in order to determine what - if anything - can be done to salvage these satellites for use in the Galileo program.
The Galileo program is the ESA's project to place a constellation of satellites in orbit that can be used for navigation on the ground. But unlike the U.S.'s GPS satellites, the ESA's Galileo program will be primarily used for civilian, rather than military, navigation.
Today, the ESA announced an update on their efforts to determine how the satellites can be used going forward. ESA ground teams have confirmed that they are in contact with the satellites and able to control them. Additionally, they've been able to successfully deploy the solar array on one of the satellites and aim to deploy the array on the second shortly.
But the real question facing the ESA is whether these satellites will be usable for the Galileo navigation program, or whether they'll have to be repurposed. A spokesperson for the ESA told me via email that it would probably be "early next week" before any solution is determined.
Both satellites are equipped with 70kg each of propellant and are capable of moving away from their current orbit. But one of the problems facing the Galileo team, the ESA spokesperson told me, is that moving the satellites to the target orbit might require the use of all of the available fuel - meaning that the life cycle of the satellites would be shortened. Additionally, he added, there may not even be enough fuel to get to the target orbit anyway.
The ESA is also investigating the possibility that the satellites might still be usable for navigation in their current orbits, but that's still being evaluated by teams on the ground. "The worst case scenario," according to the ESA, is that the satellites may not be able to be used for the Galileo program at all. But even in that case, the satellites could be put to use to "further push the limits of the system."
In any event, the spokesperson emphasized to me that this incident does not diminish ESA's commitment to get the Galileo program up and running on schedule.
"Galileo does not stop here: it is a train on tracks and will get to its final destination," he said. "This is an unfortunate and unforeseen stop in its journey but we will get the end of the journey in 2020."
