ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Spring is seen as a time of renewal. Flowers bloom. Days get longer. New life emerges. Something similar could happen on Comet 67P/Churyumov-Gerasimenko, the object of the European Space Agency's ambitious Rosetta mission. The Philae lander had a rough, bouncing touchdown on the comet late last year, leaving the intrepid machine wrapped in shadows, starved for power and hidden from view.

The main Rosetta craft has continued its scientific mission, but the ESA is optimistic the lander could come back into play as the comet nears the sun. Philae was supposed to receive 6.5 hours of light during each 12.4-hour comet day in its original landing spot. That would have meant the lander would get too hot and go out of operation in March. The current spot, however, gets just 1.3 hours of light per comet day, which is not enough to power it.

"Now we need the extra solar illumination provided by the comet's closer proximity to the sun by that time in order to bring the lander back to life," said Rosetta mission lander project manager Stephan Ulamec.

The earliest Philae might receive enough light to wake up is late March, but "it will likely be May or June before there is enough solar illumination to use its transmitter, and to re-establish a communications link with Rosetta," according to the ESA.

The ESA has narrowed down a search location for the lost lander, but has not yet confirmed a visual sighting. "Rosetta's busy science schedule is planned several months in advance, so a dedicated Philae search campaign was not built into the plan for the close flyby," said Rosetta project scientist Matt Taylor.

Even if Philae never wakes up, it still represents an exciting moment in space study, having sent back instrument data from its contact with the comet. The ESA declared its main mission "complete," but a spring revival of the lander would be a thrilling bonus.