Typically where space stuff is concerned, two hours of lost contact means your craft is almost certainly gone. But NASA just hit the long-lost spacecraft lotto.
The space agency has re-established contact with the STEREO-B spacecraft, nearly two years after communication with the Solar Terrestrial Relations Observatory (STEREO) was lost. NASA has been trying to reach the STEREO-B since Oct. 1, 2014, when the signal was dropped. But NASA took advantage of the international Deep Space Network of large radio antennas to finally reconnect to the craft.
The STEREO-B mission is designed to study the sun and its behavior, with a focus on coronal mass ejections and the geomagnetic storms it can cause when those charged particles crash into Earth’s magnetic field.
Once NASA re-established connection, the signal was monitored for several hours to figure out the craft’s condition, then it was powered back down to save battery. But at least the space agency knows the craft is still out there. The team is planning to follow a similar approach in the future, periodically checking in with STEREO-B to evaluate the craft and make sure it’s still kicking.