Rosetta Mission's Comet Lander Wakes Up From Deep Space Sleep

The next phase of a daring mission to land a spacecraft on a speeding comet was successful Friday, when the small robotic lander known as Philae reported to Earth after three years deep-space hibernation, France's National Centre for Space Studies (CNES) said.

Philae is part of a larger suite of instruments in the Rosetta Mission, which aims to deposit a spacecraft onto comet 67P/Churyumov-Gerasimenko in November of this year. The Rosetta orbiter spacecraft was taken out of sleep mode in January.

Philae, a 10-instrument probe, has been riding piggyback on the Rosetta satellite, which was launched a decade ago. The 100-kilogram spacecraft will use a system of harpoons and ice screws to anchor itself to the speeding comet once Rosetta rendezvous with it. The comet is so small that it does not exert a gravitational field strong enough to keep the probe from flying off of it.

Leading up to the anticipated August arrival at the comet, both Rosetta and Philae will undergo a series of operational checks to ensure systems are working properly, and mission controllers on Earth are standing by to deliver solutions for any problems that arise.

Rosetta and Philae had to be put into hibernation because they were sent so far away from Earth that their solar panels could not pick up enough energy to power all onboard systems. Now, after a 31-month sleep, the spacecrafts are close enough to the Sun that they could come out of sleep mode and their systems could be restarted.

"For the next three weeks, we will be inspecting the lander from every angle via telemetry link to ensure it is ready for the big day," Philippe Gaudon, Rosetta project leader at CNES, said in a statement. "By the last week of April, preparation of onboard systems will be complete. After a training phase in May and June to ready the teams for landing operations, the main task over the summer will be to select the landing site."

The mission requires extraordinary amounts of precision and expertise. Around 300 scientists from around Europe are working on the Rosetta Mission.

If all goes according to schedule, the Rosetta should go into orbit around the comet on Aug. 6; the probe's landing side will be selected after that, with a planned touchdown on the comet in November, followed by a period where the Rosetta satellite will escort the comet and attached probe for a year as it collects data about the comet's nucleus that will help scientists characterize the comet's nature and composition.