Bouncing Philae: Comet Lander May be in Trouble
New data from the European Space Agency's (ESA) historic Philae landing on the comet 67P/Churyumov-Gerasimenko has revealed that the tiny craft didn't just touchdown, it bounced, skating the surface of the rotating comet to settle pretty far away from where experts had hoped it would land.
When the touchdown signal from Philae was sent and confirmed on Nov. 12, the lander's instruments reportedly began to "think" that the craft had settled, booting up and starting a phase of passive analytic experiments.
However, expert interpretation of that data has revealed that Philae was still moving after it first hit the surface of the comet. It then bounced, skating over the cold and dusty surface of 67P for nearly two hours. It traveled about 3,300 feet (1 km) in that time. A second smaller hop at 17:32 GMT (comet time - it takes over 28 minutes for the signal to reach Earth, via Rosetta) carried it another 40 feet, where it finally settled.
This all occurred because the lander was unsuccessful in deploying its anchoring harpoons during its decent from the Rosetta comet-chasing spacecraft.
And although the Rosetta and Philae teams expressed their sheer joy that Philae had made it at all, especially considering the harpoon troubles, it now appears that the lander's unexpected bouncing has placed it in a bit of a pickle. (Scroll to read on...)
Far from the predetermined Agilkia landing site, Philae is reportedly on the "dark side" of the comet, a region where sunlight rarely shines. That could spell disaster for the lander, which boasts a solar-powered rechargeable battery for its extended mission.
"The primary battery enabling the core science goals of the lander may run out some time in the next 24 hours. As for the secondary battery, charged by solar panels on Philae, with only 1.5 hours of sunlight available to the lander each day, there is an impact on the energy budget to conduct science for a longer period of time," the ESA reported in a release.
For comparison, the original landing site offered nearly seven hours of sunlight in every 12-hour comet day.
With waning power and an unsecured spot, the lander is having trouble staying linked and relaying data to Rosetta and Earth as well.
So what to do? In the interest of collecting as much data under a potentially tight deadline as possible, ESA scientists have had the lander deploy its APXS mass spectrometer, MUPUS temperature gage, and a 25 cm drill in an effort to collect samples.
"One of the other things about the drill, they are hoping it will move the lander but they don't know how much it will move it, and they don't know if it will bring it out to get more sunshine," Monica Grady of the UK's Open University told BBC. (Scroll to read on...)
But that appears to be what the Philae team is banking on the most. Stephan Ulamec, the Philae mission manager, told reporters that he hopes the drilling will rotate the unsecured lander so that more solar panels will be exposed to the Sun before its primary battery is exhausted.
"We'll have a slightly larger panel [exposed] and this would increase the chance that at a later stage the lander could wake up again and start talking to us again," Ulamec said in an online briefing.
All is Not Lost
Despite this disappointing news and the difficulties to come, the ESA team still appears exuberant about the success of the Rosetta mission and Philae landing, during which any number of far more catastrophic problems could have occurred in the course of chasing down and then orbiting the comet 67P.
"We harnessed whole planets and their gravity to chase down the comet," Aidan Gillen said in the ESA's short film Ambition. "So many things could have gone wrong... So many unknowns... We may as well have been shooting [Rosetta] from a slingshot."
And yet here we are, with a spacecraft orbiting a comet and a robot on its surface for the first time ever. The first panoramas of Philae's stunning surroundings have even already come in, with more to come.
"We're going to be grinding our nails down waiting for the next [Philae] signal... but now we can look forward and do the science," Rosetta Project scientist Matt Taylor said during their briefing.
"We've got a year of this," he said with a chuckle. "Brilliant."
** UPDATE: Philae in the Dark but Doing Better **