As opposed to other zombiesats that just die and drift, Galaxy 15′s systems are fully functioning, with its telecommunications payload (the equipment that relays customer's transmissions around the globe) fully "on." And yet the satellite itself refuses to accept commands from Earth.
Yesterday, controllers fired a powerful signal at the satellite in an attempt not to control it, but to switch it off as it is posing a threat to other satellites in its orbital neighborhood.
If Galaxy 15 drifts too close to other satellites, it can steal their signal, thereby interrupting other vendor's services to customers on Earth. That's not too good for business, hence the increasingly desperate attempts to "kill" the satellite's power.
There are dozens of zombiesats trapped in geostationary orbit, but they all tend to drift toward two points: 105 degrees west and 75 degrees east. These are locations where the slight irregularities around the Earth's equator exert a slightly altered distribution of gravitational calm; they are the equivalent of gravitational "valleys." And it is to one of these valleys that Galaxy 15 is currently heading.