Since it was launched in October 2014, solar observatory Stereo-B was never heard from NASA. The space agency thought that the spacecraft may have lost its way in the galaxy.

Not until last Sunday, Aug. 21, when the missing spacecraft sent its first signal to its twin monitoring robot Stereo-A.

It had been 189 million miles away from the earth.

NASA picked up signals from the vehicle using Deep Space Network (DSN), a global network of huge radio antennas that can be used for communicating with spacecraft.

NASA spokesperson Karen C. Fox said NASA has worked for 22 months to attempt contact with the spacecraft.

"The DSN established a lock on the Stereo-B downlink carrier at 6:27 p.m. EDT. The downlink signal was monitored by the Mission Operations team over several hours to characterize the attitude of the spacecraft and the transmitter high voltage was powered down to save battery power," said Fox.

Before it lost contact with Stereo B, NASA implemented a hard reset that is triggered after the spacecraft goes without communications from Earth for 72 hours.

The Stereo team was testing this function when Stereo-B's line of sight to Earth was blocked by the sun.

The mission team will continue to communicate with the spacecraft in order to find out more facts that can help them control the spacecraft.