As Comet 67P/Churyumov-Gerasimenko hurdles through space, outbound from the sun, a dark passenger sits on its surface. Since July 9, 2015, Philae—the European Space Agency’s Rosetta mission’s comet lander—has remained silent.

On Jan. 10, the lander team attempted a last-ditch effort to trigger a response from the spacecraft. Via Rosetta, the team sent a command attempting to make Philae’s momentum wheel switch on.

“Time is running out, so we want to explore all possibilities,” said Stephan Ulamec, the Philae lander manager at the German Aerospace Center.

By the end of January, conditions on the comet will be “lander-hostile.” At 300 million km distance from the sun, the temperature will be less than -51 C, too cold for the lander to turn on.  

Philae’s mission has faced obstacles. In November 2014, the solar-powered Philae successfully landed on the comet’s surface but wound up on the comet’s dark side. The lander was only online for 60 hrs before it went silent.

In June 2015, sunlight became stronger and Philae came back online, but went silent again on July 9.

The comet made its closest approach to the sun in August.

“At best, the spacecraft might shake dust from its solar panels and better align itself with the sun,” said Philae’s technical manager Koen Geurts.

The German Aerospace Center team believes one of the lander’s two transmitters, and one of its two receivers have failed. The remaining transmitter and receiver no longer function smoothly, as well.

“Unfortunately, Philae’s silence does not bode well,” said Ulamec.

“There is a small chance,” said Cinzia Fanrinati, the operations manager of the German Aerospace Center team, of the last-ditch maneuver. “We want to leave no stone unturned.”

According to the German Aerospace Center, the plans for contact were executed as planned, but no signal was received. Future communication opportunities will occur twice daily until Jan. 21