Philae Lander Runs Out Of Battery, Sends Last Package of Data On Comet Makeup

The Philae probe sent what could be the last package of information for a while from comet 67P/Churyumov-Gerasimenko to its European Space Agency (ESA) handlers late Friday night, as its 64-hour battery appears to have gone kaput. Some of that data is of cometary material picked up by Philae's drilling instrument. Scientists were worried the lander wouldn't have enough juice to communicate the data to Earth after it positioned itself in a way that allows for little sunlight to hit its solar power panels.

Philae’s drill bore 10 inches into the comet and analyzed material with COSAC, short for Cometary Sampling and Composition instrument. COSAC is specifically designed to look for organic molecules. It combusts the material, “and the resultant gas fed into the analysis section, consisting of a gas chromatograph and a mass spectrometer,” according to the U.K.’s ESA information website.

Scientists suspect the lander is sitting sideways after it bounced while landing on Wednesday. The mechanisms that were supposed to anchor Philae to the comet failed. A downward thruster was supposed to fire, allowing Philae to fire a set of harpoons that would anchor it to the comet without jetting it back off the comet. Philae appears to have bounced into the shade of a cliff on the comet, although ESA scientists are still not quite sure where it is. It is getting about an hour and a half worth of sunlight every 12 hours, or each “day” on the comet. Philae could get some sunlight to get up and running again as the comet circles the Sun; the comet completes an orbit every six and a half Earth years.

Despite the landing snafu, ESA scientists call the mission a huge success. Philae completed 80 percent of its primary objectives before it began drilling on Friday, and its mothership, the Rosetta orbiter, is in perfect working condition and will continue to survey and study the comet. The ESA is apparently optimistic about Philae’s chances of waking up and continuing its work:

In the meantime, ESA scientists will analyze the data Philae sent back since landing and continue to search for the lander on the surface of the comet, which is hurtling around the sun at 41,000 mph.