Rosetta's Philae lander has made it on the surface of comet 67P but the historic landing could be a bittersweet success following malfunctions and unexpected events that occurred when the robotic probe touched down.
Philae bounced twice when it hit the comet's rugged surface and while it managed to settle back in, it has landed in a location far from its intended landing zone. The European Space Agency (ESA) is still uncertain about its exact position.
The ESA is trying to identify the lander's location using data from the Comet Nucleus Sounding Experiment by Radio-wave Transmission (CONSERT), an instrument operated on Philae and its mother spacecraft Rosetta; information gathered by the lander; and imagery from Rosetta's OSIRIS imaging system and navigation camera (NavCam).
Scientists, however, are certain that the location of the lander poses a problem to the overall mission because the probe sits in an area where it could not get sufficient sunlight for recharging its batteries.
The comet lander's initial battery-powered phase was intended to last about 64 hours and once the batteries run off, the Philae must switch to using batteries that need to be recharged using solar power. With its current location, the probe can only receive one and a half hours of sunlight daily compared with the required six to seven hours of sunlight per day.
Once Philae's batteries run out, the lander will go into hibernation mode until its batteries get more power. In its latest tweets, the Philae lander team has revealed that as anticipated, the comet lander has finally run out of power.
.@ESA_Rosetta I'm feeling a bit tired, did you get all my data? I might take a nap… #CometLanding
— Philae Lander (@Philae2014) November 15, 2014
The ESA has made Philae gather as much scientific data as it can before it ran out of power but while the battery situation will shorten the opportunity to collect information from the surface of the comet, ESA scientists remain positive. For one, the probe has already sent data and even an image from the surface of the comet. Rosetta is also working flawlessly.
The agency also said that even if the lander runs out of power, there is a possibility that the probe could be woken up again once it gets more sunlight as the comet moves closer to the sun.
"Even if its current location does not offer optimal exposure to sunlight to fully recharge the secondary batteries," the agency said, "it is possible that, as the comet approaches the sun, the illumination will increase and Philae will once more wake up and talk to us."
