Galaxy 15, the errant Intelsat ‘zombie’ satellite that went dangerously AWOL last April, is firmly back on the fleet’s official manifest and is about to start earning revenues again, perhaps as soon as January 31st.
Tobias Nassif, SVP, satellite operations and engineering at Intelsat, said January 13 ththat during all this time the satellite had worked correctly – other than it was unable to respond to ground telemetry and thus station-keeping was impossible. He confirmed that the spacecraft is now fully recovered, and near-remarkably the space walkabout has cost Galaxy-15’s mission “only by a few weeks” in terms of the craft’s full life. Galaxy-15 has an end-of-life in 2022.
The satellite was brought back under control on Christmas Eve, December 24th. Since then, Intelsat has been carrying out thorough system checks and brought the craft back to ‘normal’ mode on December 27th. On-orbit testing will now take place at a safe location (93 degrees West) and the satellite is being drifted to this location. The craft, once the checks have been carried out, will be re-located at either 129 degrees West, or 133 degrees West. That final position will be confirmed by Intelsat’s commercial division, but the craft is now firmly part of Intelsat’s operational fleet.
Galaxy 15, while it was on its rogue celestial journey, managed to pass by 15 other satellites and creating more than a few anxious moments for Intelsat, as well as the satellites whose path it was crossing.
However, skilful ground control by the operators of the craft in the way of the zombie meant no harm was done. Indeed, all now recognise that the close co-operation between Intelsat and operators such as SES World Skies, SatMex and Telesat of Canada, was in itself an object lesson for the industry generally and while ground engineers don’t want this sort of thing happening too often, there were plenty of new skills acquired. Nassif told journalists that “thousands of man-hours” were invested in the task.
Moreover, during the past near-nine months, the satellite’s builder, Orbital Sciences, has updated a handful of software patches for the rest of Orbital-supplied satellites. In other words, should this sort of problem ever occur again, then the satellite would not create the sort of headaches created by Galaxy-15.
Orbital Sciences’ engineers identified a potential 120 probable causes, now reduced to two firmware items, and the final report will emerge next month. The most likely cause, says Intelsat, is an external high-level electro-static energy burst that affected the spacecraft.