This week that determination paid off.
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.
STEREO-B was recovered using NASA's Deep Space Network -- an array of giant radio antennas that tracks interplanetary missions.
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.
The spacecrafts have already successfully revealed the structure of coronal mass ejections, which are eruptions of matter from the sun so powerful they can disrupt satellites.