Zombie satellite wakes up after drifting incommunicado for nine months

BBC : A telecommunications satellite that had been adrift and incommunicado since last April has abruptly recovered its ability to respond to commands. Launched in 2005, Intelsat’s Galaxy-15 had been relaying TV signals to the Americas from a geostationary orbit above the Pacific Ocean. Maintaining such an orbit requires a spacecraft to periodically fire its thrusters in response to commands from the ground station. During its mysterious hiatus, Galaxy-15 had drifted from its orbital perch and was becoming a threat to other satellites before its equally mysterious reawakening. Because Galaxy-15 had lost only its ability to communicate but not its other functions, it acquired the nickname Zombie-sat.