Although the European Space Agency’s Rosetta mission was a resounding success, and its comet lander Philae produced reams of valuable data on comet 67P/Churyumov-Gerasimenko in November 2014, the refrigerator-sized planetary lab went silent around six months ago.
Mission controllers were worried after the comet lander’s thruster glitched, caused it graze a crater rim and make a near-crash landing, but the lab survived the rough landing and began sending back data shortly thereafter. However, Philae could only transmit for a limited time until it’s batteries ran low. The ESA’s mobile lab apparently landed in a shaded area, as its solar panels are not charging.
Philae’s decade-long mission to deep interplanetary space
Unfortunately, Philae has remained silent for half a year now. “The last clear sign of life was received from Philae on July 9, 2015,” the German Space Agency said in a statement earlier this week. “Since then it has remained silent.”
The controllers recently transmitted a command to the robot lab to spin up its flywheel, which was used to stabilize the probe when it first landed.
They are hoping this will “shake dust from its solar panels and better align it with the Sun”, according to technical project manager Koen Geurts.
The bad news us that the command (which is sent via the orbiting Rosetta spacecraft) may never even reach Philae.
Geurts continued to note that several further attempts will be made to contact the lander.
Last-ditch effort to save Philae
“It’s an admittedly desperate move,” Philippe Gaudon of the French National Space Agency noted in an interview with the press. “It is very unlikely the robot will become functional again.”
One key problem is that it’s likely one of the lander’s two radio transmitters, and possibly a receiver as well, is no longer working. Moreover, the ones that are working are apparently not fully functional.
The opportunity to make contact with Philae will be gone by the end of January, when the comet and lander will have traveled some 185 million miles away from the Sun.
The temperature will the drop below minus 51 degrees Celsius/minus 60 degrees Fahrenheit, where its systems will freeze up and no longer operate.
The robot lab was equipped with a dozen instruments and redundant communication equipment, and spent 6.5-billion-kilometre journey to the comet as a passenger on mothership Rosetta.
During the landing, Philae bounced on the craggy surface and ended up angled in deep shade. The lab sent back data for 60 hours until the batteries ran low and it entered into standby mode.
However, as the comet flew closer to the Sun, the solar panels were exposed to light, and Philae woke up on June 13th, 2014. It managed to send data back intermittently for almost a month, but fell silent again on July 9th.
Of interest, one of the main goals of the comet probe was to learn more about the origins of life on Earth. That’s because comets are relatively pristine holdovers from the formation of the solar system some four ad a half billion years ago. According to some planetary astronomers, it is likely that numerous comets hit the Earth in the first few hundred million years of its life, providing both water and the chemical building blocks for life.
Related to this, Philae has identified several organic molecules in 67P, and four have never been detected before in a comet.