Philae comet lander comes back to life after 200-day hibernation

Posted on 17 Jun 2015 by Michael Cruickshank

The European Space Agency (ESA) has confirmed that it has managed to re-establish contact with its Philae comet lander.

Philae had been in a hibernation mode for 211 days on the surface of comet 67P/Churyumov–Gerasimenko.

“On the evening of 13 June, a weak but solid radio link between Rosetta and the lander was finally established for 85 seconds,” explained the ESA in a press statement.

Designed to study the composition of comets and their unique geology as part of the larger Rosetta mission, Philae was the first probe to ever land on a comet – a feat which it achieved on November 12 last year.

Shortly after it touched down however, the ESA noticed that the craft had actually bounced across the surface of the comet, leaving it in a heavily shaded region. This meant that the craft was unable to generate enough solar power to continue long-term operations.

After most scientific experiments were carried out using the remaining battery power, ESA controllers put Philae into a standby mode, in the hope that its solar power generation would increase as the comet traveled closer to the sun.

These hopes appear to be well-placed, and initial telemetry data from the Philae lander appears to show that it is in a reasonably good condition.

“We are still examining the housekeeping information […] but we can already tell that all lander subsystems are working nominally, with no apparent degradation after more than half a year hiding out on the comet’s frozen surface,” said Stephan Ulamec, Philae Lander Project Manager.

The ESA is now scrambling its resources to establish stable contact with the lander, and determine what course of action to take next. For this, plans are being made to optimise the path of the Rosetta spacecraft, which is in orbit around the comet, in order to facilitate easier communication between the lander and Earth.

Once this has been achieved, the ESA is then likely attempt to carry out the science experiments which failed earlier in the year due to a lack of power.

The most important of these – an onboard drill – will attempt to take a sample of the material which makes up the surface of comet 67P/Churyumov–Gerasimenko.

The next period of communication with Philae is expected to occur on today or tomorrow.