Time Is Running Out for Lost Philae Lander
Rosetta's Philae lander touched down on a comet for the first time on Wednesday to collective cheers around the world. While the landing was a historic achievement in itself, the mission scientists were hoping to mine as much data about the comet as they possibly could from the lander. But unfortunately, the mission might be cut short, as we still have not been able to locate the lander, and the slightly troubled landing may cause the batteries to die prematurely.
There were a few mishaps during the landing, including a failure of its harpoons to deploy correctly and anchor it to the comet, causing the lander to bounce a little bit before settling into a stable position. But at long last, the lander re-established communication with Earth, sending back the first picture of the surface of a comet and confirming that several of its instruments were operational, including the drill that would penetrate the surface of the comet and collect valuable samples.
However, as a result of that bounce, Philae ultimately settled down in a shadowy area, believed to be in the shadow of a cliff, which both makes the lander more difficult to locate and, more significantly, means that its solar panels are not getting enough light to sustain its secondary batteries for very much longer. Philae left Earth with a 60-hour battery charge, and the panels are only getting 1.5 hours of sunlight per day as opposed to the estimated 6-7 hours, so in all likelihood the batteries will die at some point this evening.
.@Philae2014 you're in a shadow? How am I supposed to spot you there?! Our teams working hard to find you :)— ESA Rosetta Mission (@ESA_Rosetta) November 13, 2014
"We still could not exactly identify where Philae is at this very moment," Philae Lander Manager Stephan Ulamec said this morning.
ESA researchers are still awaiting images from Rosetta's OSIRIS camera from the period that Philae was "bouncing" on the surface of the comet, which could shed light on the lander's location. "So hopefully... we'll soon be in the position to know where it hides," said Holger Sierks, who oversees OSIRIS. Once they locate the lander, they may try to move it or rotate one of its solar panels in order to prolong its battery life.
"We plan to rotate the lander a little bit so that at the position where we have now this one panel that gets sun, we'll have a slightly larger panel and this would increase the chance that at a later stage the lander could wake up again and start talking to us again," said Ulamec.
Although Philae is confirmed to be collecting samples, the main concern is that the battery will die before the lander has a chance to analyze those samples and send the data back to Earth. In that case, the data will be in Philae somewhere, but humanity won't have access to it unless we can re-establish communication with the lander at some point, which would be unlikely. When the comet gets too close to the sun later this year, Philae will certainly die, although there is a chance that there will be a tiny window of opportunity for Philae to talk to us when the heat activates the batteries via the solar panels but hasn't become so intense that Philae is unable to function. This is only a hypothesis, however, and there is every chance that if Philae runs out of battery tonight, we'll never hear from it again.