Rosetta, the probe that made the historic first launch of a man-made machine to a comet last year, has made its first attempts to contact its lost lander, but to no avail.

When the lander Philae touched down on Comet 67P/Churyumov-Gerasimenko last year, scientists were both elated and frustrated. The historic event was marred by the fact that Philae landed in a crevasse where its solar cells could not get enough power to function. The lander ran off battery power for 54 hours before cutting off communication, and has not been heard from since.

Although working for only a short amount of time, Philae was still able to set all ten of its onboard instruments to work and to beam back data to the European Space Agency (ESA). Since then, however, the deep crack in which Philae landed has prevented it from using its solar cells to recharge or send any other information.

The ESA announced on March 10 that conditions were favorable to attempt to contact the sleeping lander, in the hopes that it has had time to come out of hibernation. Philae will only wake up completely when it has access to five watts of energy and an internal temperature above negative 45 degrees Celsius.

The Rosetta probe beamed instructions to Philae “to most effectively divide the available solar power between heating and communications.” It did not receive a response, but this could mean one of two things: either the lander does not have sufficient energy available to activate its radio but still received the message, or it was in such a state that it could not even receive Rosetta’s commands.

A statement by the ESA on its blog said, “Perhaps it is still too cold for the Philae lander to wake up. Maybe its power resources are not yet sufficient to send a signal to the team at the DLR Lander Control Center.”

“We have to be patient,” said DLR project manager Stephan Ulamec. Scientists speculate that Philae will have enough energy and heat wake up and contact Rosetta by September.