After thousands of attempts to send a "shut down" command to the telecommunications payload, satellite controllers admitted defeat; Galaxy 15 was a zombie, drifting uncontrolled past other satellites in their geostationary orbits, potentially sapping their signals.
The Problematic C-band
So, on May 23, Galaxy 15 will drift into the orbital slot of AMC-11, a satellite owned by SES World Skies that distributes cable television throughout the USA. Unfortunately, both Galaxy 15 and AMC-11 process "C-band" signals, meaning they operate on the same frequencies.
Why is this a problem? Peter B. de Selding over at Space.com explains:
Satellites like Galaxy 15 and AMC-11 are so-called "bent-pipe" designs that receive signals from the ground, amplify them on board and redistribute them to customers' ground antennas. Emptied of its customers - except one, the U.S. Federal Aviation Administration, which uses an L-band payload on Galaxy 15 to guide aircraft landings - Galaxy 15 is no longer broadcasting. But its electronics payload is ready to capture and rebroadcast signals it receives that are intended for other spacecraft.
So the signal intended to be distributed via AMC-11 for U.S. cable TV customers could experience significant interference as Galaxy 15 drifts through AMC-11′s orbital slot (although one would think there would be a back-up satellite?). So if you're sitting down to watch the season finale of Lost and you notice some flickering on your TV, don't start hitting your set-top box in the hope it's a glitch, the problem is actually 22,400 miles above your head.
Lost in Space Weather
Although this issue is hardly life-threatening, it is a wake-up call.
Life on our planet has evolved inside the sun's tumultuous atmosphere for billions of years, obviously we are fairly well protected by Earth's thick atmosphere and global magnetic field.
Unfortunately it's our hunger for more advanced, yet increasingly vulnerable, technologies that could prove to be modern society's Achilles heel. Today it's cable TV, the next big solar storm could knock out critical global positioning satellites, international communication networks or even national power grids.
Many technologies may never be fully shielded against solar temper tantrums, but space weather prediction techniques must be better funded so we can understand how to mitigate the risk of damage to our armada of satellites.
NASA, National Oceanic and Atmospheric Administration (NOAA) and the European Space Agency (ESA) are acutely aware of the risks and have tasked many research groups to improve our solar physics knowledge, but for governments to take space weather seriously, it will probably take something a more dramatic than a cable TV outage to make them sign bigger research funding checks.
NASA's Solar Dynamics Observatory is one such high profile mission to keep an eye on the sun, but obviously more needs to be done before more "unprecedented" events like the possible interruption of the Lost finale cause some serious damage.
Image (top): The Galaxy 15 satellite before being launched in 2005 (Orbital Sciences)