NASA lost a probe in space for two years– and they just reconnected

After a 22-month long search, NASA was able to re-establish contact with STEREO-B Sunday evening, locking onto the spacecraft’s signal using its Deep Space Network (DSN) tracking tool and receiving its transmissions for the first time since October 1, 2014.

STEREO-B, which is part of the US space agency’s Solar and Terrestrial Relations Observatory mission, lost contact with the mission control team while working alongside its sister spacecraft measuring the energy of solar emissions traveling towards Earth from multiple angles.

“The DSN established a lock on the STEREO-B downlink carrier at 6:27pm EDT,” NASA said in a statement. The signal “was monitored… over several hours to characterize the attitude of the spacecraft and then transmitter high voltage was powered down to save battery power,” and now the team is working on a plan to evaluate and regain full control of the lost probe.

Agency still needs to make sure the spacecraft is in good health

According to Mashable and Gizmodo, STEREO-A and B launched in October 2006 as part of a proposed two-year mission, during which one would measure the sun’s energy output  from just within Earth’s orbit and the other would be on the outskirts of the planet’s path around the sun – marking the first time that scientists would be able to collect such data.

However, NASA officials lost contact with STEREO-B after a test of its equipment failed to go as planned, and the probe was unable to turn itself back on as expected after rebooting itself due to receiving no signal from Earth for 72 hours. Team members heard a weak signal immediately after that hard reset, but then the spacecraft remained silent – until this weekend, that is.

NASA reestablished contact with the STEREO B spacecraft. (Credit: NASA Goddard)

NASA reestablished contact with the STEREO B spacecraft. (Credit: NASA Goddard)

The agency conducted the test of the reset function in preparation for a phenomenon known as a solar conjunction, in which STEREO-B would drift to the side of the sun opposite from the Earth and thus would be unable to communicate with mission control personnel. Those tests obviously did not go as planned, and scientists have hypothesized that it was because of a sensor issue on STEREO-B caused it to go spinning out of control, preventing its solar panels to receive enough energy to keep the probe adequately charged, according to Gizmodo.

While the fact that NASA has reestablished contact with the spacecraft is good news, Mashable points out that STEREO-B is not exactly in the clear just yet. The agency needs to determine if it is in good health and whether or not it is still capable of conducting its solar energy research after so much downtime. The fact that it has made contact with Earth at all is “promising,” though, the website added.


Image credit: NASA Goddard