LONDON — Two of the world's largest satellite companies say they're scrambling to keep an out-of-control communications satellite from drifting into another satellite's orbit and interfering with cable programming across the United States.
Intelsat said it lost control of the Galaxy 15 satellite on April 5, possibly because the satellite's systems were knocked out by a solar storm. Intelsat cannot remotely steer the satellite to remain in its orbit, so Galaxy 15 is creeping toward the adjacent path of another TV communications satellite that serves U.S. cable companies.
Galaxy 15 continues to receive and transmit satellite signals, and they will probably interfere with the second satellite, known as AMC 11, if Galaxy 15 drifts into its orbit as expected around May 23, according to the two satellite companies.
AMC 11 receives digital programming from cable television channels and transmits it to all U.S. cable networks from its orbit 22,000 miles (36,000 kilometers) above the equator, SES World Skies said. It operates on the same frequencies as Galaxy 15.
"That fact means that there is likely to be some kind of interference," SES World Skies spokesman Yves Feltes told The Associated Press. "Our aim is to bring any interference down to zero."
He would not name any of the cable television channels or providers that could be affected or say how long the interference could last.
However, AMC 11 is part of a satellite constellation that transmits HD television signals for more than 100 channels, ranging from Showtime and MTV Networks to HSN and the Food Network. Among the channels carried by Galaxy 15 and its sibling satellites are Cinemax, Encore, ESPN, Fox News Channel, HBO, Starz and SyFy.
DirecTV Inc., the largest US satellite TV company, said it will not be affected. Comcast Corp. said it was monitoring the situation. Cox Communications Inc. said it could not immediately specify if its service would be affected and Dish Network Corp., Time Warner Cable Inc., Charter Communications Inc. and Cablevision Systems Corp. had no statements on the matter or did not return Associated Press calls seeking comment.
"We are confident that service disruptions will be minimized or avoided," said Dianne VanBeber, a spokeswoman for Intelsat.
How to minimize disruptions
Galaxy 15 is floating over the Pacific Ocean slightly to the east of Hawaii, said Emmet Fletcher, space surveillance and tracking manager for the Space Situational Awareness Program at the European Space Agency. He said Galaxy 15 was highly unusual because it continued to send out television signals, unlike other malfunctioning satellites that automatically went into complete shutdown when their navigational systems malfunctioned.
Slideshow: Month in Space: January 2014 Last week, SES World Skies said that the period that poses the greatest risk of interference for AMC 11 customers would be May 31 to June 1.
SES' Yves Feltes said one option to prevent interference would be to use AMC 11's propulsion system to shift the satellite about 60 miles (100 kilometers) away, to an orbit that's still within its carefully prescribed "orbital box" but as far away as possible from Galaxy 15.
He said SES had other strategies under consideration but declined to provide details. "We have all of our technicians, all of our specialists on this case," he said.
Both companies said there was no risk of an actual collision between the two satellites in space.
Intelsat said it was analyzing signals from Galaxy 15 daily in order to predict its trajectory and was trying to figure out if it can shut down the satellite's transmission so it would not interfere with AMC 11. VanBeber said cable companies could also adjust their equipment in order to minimize any interference.
Turning into a zombie satellite
She said satellites like Galaxy 15 today cost $250 million to build, launch and insure, but the satellite probably cost less when it was launched in 2005.
Feltes said the two satellite companies, both based in Luxembourg, were cooperating closely. "They have tried numerous things to regain control of the satellite or to have it finally shut down," he said. "It needs some collaboration to bring the impact of this failure to an absolute minimum."
Eventually, Galaxy 15 is expected to drift into one of two gravity wells in Earth orbit that capture most out-of-control satellites. About 150 to 200 such "zombiesats" are already oscillating around those orbital points.
This report includes information from The Associated Press and msnbc.com.
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