Comet probe Philae reawakens after seven-month sleep

Healthy and ready to do science work

After seven months in hibernation on the dark side of the comet 67P/Churyumov-Gerasimenko, the European Space Agency's Philae probe has reawakened and is ready to do science work.

The lander originally touched down on the comet on 12 November 2014 after a 10-year journey through space. It was supposed to harpoon itself into place, but instead bounced off the surface of the ball of ice several times before settling in a dark ditch where its solar panels couldn't receive sunlight.

Now, however, the comet has travelled closer to the Sun and the solar panels have charged the lander's battery enough for it to reboot and make contact. Two previous bids to make contact in March and April failed, but a new attempt was launched in May.

Healthy

"We got a two-minute… successful communication" at 2228 Central European Time (2028 GMT) on Saturday, mission manager Patrick Martin told AFP from the operations centre in Madrid. "This was sufficient to confirm that Philae is healthy and that its sub-systems are OK in terms of energy and temperature for ongoing communication with [its mothership] Rosetta."

Stephan Ulamec, Philae project manager with the German space agency DLR said that the lander is now ready for scientific operations, but Martin was more cautious - saying: "We have already lined up more communication windows which hopefully will see a repeat of this successful communication. If we get a stable communications pattern we should be able within a week or so to think about operating the instruments on board the lander."

The 100kg probe will ride aboard the comet as it reaches its closest point to the Sun on 13 August 2015, then we're not quite sure what will happen. It'll be tough to find out, too, as the comet will likely become too hot for the lander to operate. The end of mission is scheduled for December, but if the comet doesn't disintegrate under the stress of its solar fly-by then it'll head back out of the inner solar system, taking a rather toasted Philae with it.