article image

Thank you and goodnight! Philae's power levels plunge

Paul Sutherland, Feature writer
Nov 15, 2014, 9:08 UTC

Sen—Power levels from Rosetta’s Philae lander suddenly plunged tonight, indicating that its main battery was losing charge. 

It was the moment space scientists knew must come. And it could spell the end for the little craft.

Space scientists had been racing against time to gather as much data as they could from all the ten experiments on board Philae. 

Before power failed they managed to collect all data returned from COSAC—the COmetary SAmpling and Composition experiment—that was designed to detect and identify complex organic molecules on the comet.

They even managed to operate the drill that was sent to dig inside the icy surface and discover secrets kept frozen from the earliest days of the Solar System.

Philae has not died, but instead gone into a kind of hibernation. It was supposed to be kept alive by the power of sunlight charging a secondary set of batteries, but its landing position prevented it from receiving enough sun.

In theory, the probe could be awoken later if the comet’s “season” changes and more sunlight reaches it. But it seems a major amount would be needed.

Of the latest day’s science results, Stephan Ulamec, Philae’s lander manager, said: “We’ve got data—all the house-keeping data and data from COSAC—although we’ve no idea what’s in there yet. The drill (SD2) moved up and down, but again, we don’t yet know what we have.”

The ESA team were also successful in rotating Philae in a bid to change the orientation of the solar panels so that they could receive more sunlight fuel.

Ulamec said: “We did the lift and turn. The landing gear lifted by about 4 cm, and we turned about 35 degrees.

“The carousel of Ptolemy was also turned and we are running Ptolemy for a concentrated ‘sniff’.”

Meanwhile it was revealed that Philae first landed almost exactly where it was meant to. Images from Rosetta’s NAVCAM show a dark disturbance in the zone that suggests it is the probe touching down and possibly raising dust.