In-Orbit Maneuvers Likely Needed to Avoid Intelsat Satellite Interference, SES Says
SES said it’s considering several different in-orbit maneuvers to mitigate interference on subsidiary SES World Skies’ AMC-11 satellite from the nearby Intelsat Galaxy 15 satellite that’s unresponsive and continuing to transmit while slowly drifting outside its slot (CD April 9 p10). The amount of interference created by the proximity of the two C-band payloads is hard to estimate, but the company is considering a number of movements that should keep interference at a minimum as Galaxy 15 passes through AMC-11’s orbital spot at 129 degrees west, said a company spokesman.
Sign up for a free preview to unlock the rest of this article
Export Compliance Daily combines U.S. export control news, foreign border import regulation and policy developments into a single daily information service that reliably informs its trade professional readers about important current issues affecting their operations.
"There are a number of scenarios that should bring interference down to minimum,” the spokesman said. “Is [the interference] going to be perceptible on the ground? Nobody really knows, quite honestly.” In the meantime, SES has had close contact with Intelsat and its customers on AMC-11, he said. Estimates of Galaxy 15’s drift say the stray satellite will enter AMC-11’s orbital box around early June and the company has until then to decide on a plan, the spokesman said. SES will also urge AMC-11 customers, largely cable feeds, to switch to different uplink facilities in an effort to increase “accuracy of the signal going to satellite to allow more flexibility in moving [AMC-11] in geostationary arc,” he said.
Following several failed attempts to shut down the unresponsive but active Intelsat satellite Monday, Intelsat will let the satellite drift outside its orbital slot, the company said. It will continue to work to mitigate interference with nearby satellites as it drifts through space but has “temporarily suspended the recovery and disabling activities” until it passes through the orbital slot of the AMC-11 satellite, a company spokeswoman said. Intelsat isn’t aware of any interference the satellite caused, she said. Monday’s attempts were high power signal blasts that yielded no response, she said. Intelsat will continue send standard satellite operator communications to Galaxy 15 which, unlike the signals sent Monday, don’t pose a threat of interference, she said. Once the satellite passes through the 129 degrees west slot, it won’t pose an interference problem to nearby satellites, she said.
Orbital Sciences, the satellite’s builder, is working closely with Intelsat to help control interference with surrounding satellites and potentially recover the satellite if communications return, said a company spokesman. “First and foremost our goal is to help the customer in any way we can,” he said. “We are working hand in glove with the customer."
The FCC is aware of the drifting satellite and has been providing special temporary authority (STA) for the Galaxy 15’s movement as well as the movement of replacement satellite Galaxy 12, agency officials said. Outside of authorizing the STAs, the agency wasn’t asked for other involvement, they said.
Galaxy 15 was at 133 degrees west and primarily used by North American cable programmers, who were moved once the satellite stopped responding, Intelsat has said. Galaxy 15, which had an expected service life of 17 years, was launched in 2005 and has 24 C-band transponders.