Nearly two years ago, NASA lost contact with the STEREO-B spacecraft operating as part of its STEREO Mission.
The space agency has been trying to reestablish contact with that spacecraft since then, and now, about 22 months later, NASA has announced that it succeeded.
NASA made contact with the spacecraft yesterday, and it will soon perform further tasks to determine STEREO-B's health, status, and other pertinent information.
STEREO, in this case, stands for Solar Terrestrial Relations Observatories; you can find out more information about the mission in general here.
Back on October 1, 2014, NASA lost its contact with the STEREO-B spacecraft, and though attempts to reestablish communications hadn't been successful, it had continued efforts to recover the spacecraft.
Most recently, NASA used its Deep Space Network to try to recover the mission, which proved successful yesterday at 6:27PM Eastern time.