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One giant leap! Philae bounced 1km off surface of comet

Paul Sutherland, Feature writer
Nov 13, 2014, 18:42 UTC, Updated Nov 13, 2014, 20:27 UTC

Sen—Mission Control, Darmstadt, Germany—Rosetta's companion probe Philae made an astonishing bounce up to one kilometre high off the surface of Comet 67P/Churyumov-Gerasimenko on its first landing, it was revealed today.

The European Space Agency's Rosetta mission's piggyback partner did not touch down again for another two hours, before bouncing off again for six or seven minutes. 

Finally the fridge-sized craft settled back onto the boulder-strewn ground and became what European scientists at mission control in Darmstadt, Germany, describe as stable. 

Today they released the first photo taken by Philae from the comet's surface. It shows that the landing spot is definitely not as flat as they had hoped. One of the landing feet is in the picture and looks precariously placed.

The good news for the team is that the probe is definitely alive and sending back valuable information and pictures from the comet. 

They know this because they received continuous data overnight via the Rosetta mothership in orbit around the comet.

But they do not yet know exactly where on the surface of the 4.5 mile long, peanut-shaped comet the tiny probe is, following its huge bounce. Rosetta's high-resolution OSIRIS camera is scouring the landscape to try to find it.

Philae is alive and working on the surface of the comet, scientists said today. But it could be stuck like a car in a ditch.

Harpoons failed to fire to pull the probe to a secure landing yesterday, and it bounced twice before coming to rest.


Still upbeat. Sen news editor Paul Sutherland with Rosetta's chief scientist Matt Taylor, right, at mission control, Darmstadt, Germany. Image credit: Steve Young

And instead of sitting on a flat region, Philae is in a very irregular terrain—exactly the sort of place ESA did not want it to be.

A photo taken at local sunrise, shows one of the feet lifted off the ground. There are also fears that its solar panels that charge its batteries are badly placed to receive sunlight.

They are receiving only one and a half hours of sunlight every 12 hours which is not enough to keep them topped up, though that might improve as the comet's orientation in space changes too.

But the probe and its main battery are operating well, it was reported at the French mission centre in Toulouse. Eight of the probe's ten experiments are working and returning valuable data to Earth via the orbiting Rosetta probe.

ESA has decided not to use another experiment that was meant drill 20 cm (8 in) into the surface of the comet for the moment. That is because they fear it could make the lander spin or push it back into space, plus it would drain a lot of its precious power.

Philae landed with enough power on board to operate for two and a half days, and then continue for longer depending on how much sunlight it got to charge up its batteries. 

The other is  the Multi-Purpose Sensor for Surface and Subsurface Science (Mupus) which was meant to measure the density, thermal and mechanical properties of the surface. It is feared it could destabilise the probe if it is extended.

ESA will get as much science done as it can with Philae in its present position. After that, they are planning try to fire the harpoon in a final bid to anchor the probe firmly to the comet.