(CNN) Despite almost two years of silence, NASA never stopped searching for its long lost spacecraft STEREO-B.

This week that determination paid off.

Spacecraft STEREO-A and STEREO-B are studying the sun.

Lost...

NASA announced Sunday that it had re-established contact with STEREO-B after communications were lost in October 2014.

Contact with the spacecraft -- which works in tandem with a second spacecraft STEREO-A to study the sun -- was lost during a test of one of its timers.

Scientists had been testing the timer when STEREO-B's line of sight and communication to Earth was blocked by the sun.

Meanwhile STEREO-A was unaffected by testing, and continued working normally over the past 22 months.

...and found

STEREO-B was recovered using NASA's Deep Space Network -- an array of giant radio antennas that tracks interplanetary missions.

The positions of STEREO-A, shown in red, and STEREO-B, shown in blue.

Now contact has been reestablished, the STEREO team will continue monitoring the spacecraft to see what kind of state it's in.

What is the STEREO mission?

Launched in October 2006, the STEREO mission includes two spacecraft -- one ahead of Earth in its orbit, the other behind -- tasked with monitoring the flow of energy and matter from the sun to Earth.