Nasa has re-established contact with one of its solar terrestrial relations observatories, known as STEREO-B spacecraft, after a gap of nearly two years.

After losing communication with STEREO-B in October 2014, Nasa has been making several attempts to get in touch with the Sun-watching spacecraft.

Conducted using the agency’s deep space network (DSN), the STEREO team has been able to recover STEREO-B during a recent attempt.

During the recovery mission, the DSN has established a lock on the STEREO-B downlink carrier.

"Launched in 2006, the STEREO mission is Nasa’s third mission under its solar terrestrial probes programme (STP)."

After locking the downlink signal, the mission operations team kept observing it for several hours to characterise the attitude of the spacecraft.

The high-voltage transmitter was also powered down to save the spacecraft’s battery power.

The STEREO missions’ operations team is also planning to continue further recovery processes to evaluate observatory health of STEREO-B.

They also plan to re-establish attitude control, as well as evaluate all subsystems and instruments of the spacecraft, which continues to work normally.

Nasa said that it had lost contact with STEREO-B while testing the spacecraft’s command loss timer, which is a reset that is activated after the spacecraft goes without communications from Earth for 72h.

Launched in 2006, the STEREO mission is Nasa’s third mission under its solar terrestrial probes programme (STP).

With two similar observatories, including one ahead of earth in its orbit, while the other trailing behind, the mission provides new information on the Sun-Earth system.

Image: Nasa re-established contact with the sun-watching STEREO-B spacecraft. Photo: courtesy of Nasa.