Philae to start drilling

Scientists have started drilling into comet 67P/Churyumov-Gerasimenko amid fears that the battery aboard Philae will die within the next day. The European Space Agency (ESA) uploaded commands today to tell Philae to deploy its drill in the hope that it can retrieve  some samples to analyse in the robot's onboard laboratories. But there is a risk: the torque could destabilise the delicately placed lander. The drill is believed to have reached 200mm into the comet before signal with the lander was lost. Following its successful landing and subsequent bounce, Philae has settled in the shadow of a cliff and is not receiving the sunlight it needs to recharge its batteries. Scientists believe it's battery will not last beyond Friday night's radio contact. It is hoped all the science data can be retrieved by then. Analysis of the communications between Philae and Rosetta have enabled scientists to produce a circle of uncertainty within which Philae almost certainly lies. Follow-up imagery from the orbiter should find the lander's position. Paolo Ferri, the head of mission operations at the ESA is confident that engineers can find an answer to Philae's power shortage: one idea to be tried on Friday is to turn the main body of the robot to show the largest of its solar panels to the Sun in the hope of  eking out some more life for the lander. Valentina Lommats, of the lander control centre DLR, says another option is to bounce the lander, although it could be difficult as the lander is surrounded by rocks. @Philae2014 tweeted at 10.15am "Last night MUPUS hammered the penetrator into the ground. APXS also got to work! My team is currently checking how they did #CometLanding" MUPUS (Multi-Purpose Sensors for Surface and Subsurface Science) uses sensors on the Lander's anchor, probe and exterior to measure the density, thermal and mechanical properties of the surface. The APXS instrument - Alpha Proton X-ray Spectrometer - will determine the chemical composition of the Philae landing site by firing alpha particles at the surface and catching what bounces back. Different chemicals react in different ways and so the composition can be determined.