At nearly the last moment, the ESA finds their lost Philae lander
Who would have ever thought that a remote, three-legged box the size of a dishwasher would have such a flair for the dramatic? This isn’t to downplay the significance of the first man-made object to be landed (or bounced?) on the surface of a comet, but the ongoing misadventures of the Philae lander on Comet 67P have proven to be exciting up to the last minute. With less than a month in the mission, the team behind the Rosetta spacecraft have finally located Philae among the icy boulders covering the comet, confirming a tale of literal ups and downs over ten years in the making.
The original mission plans called for Philae to land on Comet 67P, having been transported through the solar system by the Rosetta spacecraft for a decade. While the rendezvous with the comet started as planned, Philae’s long-awaited landing went awry, with tethers failing and the whole craft bouncing off the surface of the comet. Landing some two hours later, the lander only functioned for three days, as it came to rest in the shadow of some rocks and couldn’t get enough sunlight to recharge its batteries. There was a glimmer of hope in June of 2015, but by February of this year mission commanders accepted that Philae was now in permanent hibernation mode, lost due to a lack of power rather than damage from the landing.
Absent but not abandoned
That didn’t mean that the ESA was really done with Philae though. The Rosetta spacecraft has been orbiting closer and closer to Comet 67P, collecting data and sending increasingly detailed photos back to Earth. For a long time, those photos have been taken from too far from the comet’s surface to identify Philae’s landing location, especially since the surface is littered with Philae-sized rocks and their shadows. Now that Rosetta has moved to a tighter, 1.7-mile orbit, new pictures have finally revealed the lost lander. The keen eyes of the European Space Agency’s (ESA) Cecilia Tubiana found Philae wedged next to a large boulder, one distinct leg sticking out of the shadows to wave its last goodbye. (Sorry…drama, you know?)
Aside from the sense of closure, this discovery greatly improves all of the data gathered by Philae before its batteries ran out. Various readings about Comet 67P were transmitted home, but they all carried the caveat that we didn’t know exactly where they corresponded with on the comet. Being able to confirm this location allows for all that data to be better contextualized, increasing its scientific utility. So while Philae kept us hanging on until nearly the last minute, the lander will be going out on a high note before the mission ends with Rosetta’s planned collision on September 30th.
My second grader asked: How far did the lander bounce so they couldn’t find it?
Philae traveled a little over half a mile by the time it settled into it’s final location. The first thirty minutes of that movement were actually caught on camera by Rosetta, but pinning down a specific location was difficult. Researchers have been eliminating possible sites for months, and so for Philae to be found under a boulder in the photographed region wasn’t a complete surprise, but it wasn’t exactly expected at this point either.
Source: Philae Found!, ESA Rosetta