Rosetta: Scientists mull ‘hopping’ Philae probe on comet surface

Scientists racing against time to save the Philae probe 500m km away from Earth are actively considering taking a last-ditch gamble and “hopping” the lander on the surface of the comet it sits on.

Mission controllers have less than 24 hours before the craft’s primary battery power runs out.

Because the lander is shrouded in shadow, it will not be able to recharge the batteries using electricity generated by its solar panels.

A risky solution would be to use the probe’s landing gear to “hop” to a sunnier spot, or shift the craft by activating moving parts linked to its instruments.

British scientist Professor Ian Wright, lead investigator for Philae's Ptolemy instrument that is designed to analyse the composition of surface and dust samples, said: "The hopping idea is being actively considered.

“There’s no manual for this. We’re having to respond to what we think we’re dealing with. The balance we have to strike is using power to rescue the craft and using power to do some science.

“There’s no rule book for this stuff. People are very tired and thinking about it as well as they can.

“Clearly we’re potentially heading towards the end, but if we could get it out into a bit more sunlight then things will improve.

“In actual fact these movements don’t take up a lot of power. There is a slight worry that if you try to move something it might make things worse.

“It might topple over. But clearly if you’re getting to the end there’s no harm in having a go.

‘Complete unknown’

“It’s a complete unknown but clearly we should be taking risks. There’s no point in not doing that.”

The dishwasher-sized craft made a dramatic landing on comet 67P/Churyumov-Gerasimenko on Wednesday after an epic 10-year, four billion-mile journey through space aboard the Rosetta mothership.

Two harpoons that were supposed to anchor Philae to the surface failed to deploy, and the probe bounced a kilometre (0.6 miles) into space, floating above the comet for nearly two hours. Eventually gravity drew it down and it bounced again, coming to rest close to the wall of a large crater more than half a mile from the original landing site.

Scientists believe it is positioned at an angle with one of its three spidery legs suspended in space. The cliff-like crater wall has cast a dark shadow on the probe that is now the scientists’ greatest worry.

Instead of the expected six or seven hours of sunlight per 12-hour day, Philae is only receiving one and a half hours.

Press Association