Like a prodigal son returned, the signals of the believed lost STEREO-B spacecraft have been joyfully received by NASA engineers indicating that the solar observing spacecraft is still alive. STEREO-B signal was recovered at 2227 GMT on 21 August 2016 after being apparently lost since October 2014.
The STEREO-B (STEREO-BEHIND) spacecraft was thought to have failed after a loss of contact on 1 October 2014. This loss of contact occurred due to a guidance and control fault following a planned computer reset during orientation system testing. Engineers are now recovering the spacecraft back from retirement.
STEREO B is one of a pair of spacecraft located in roughly the same heliocentric orbit as Earth – one ahead of Earth (STEREO A) and one behind (STEREO B). Over time they have both moved around the orbit away from Earth. Launched in 2006, the pair was designed to trace the flow of energy and matter from the sun to the Earth and reveal the true three-dimensional structure of coronal mass ejections and show why they happen.