The European Space Agency’s Philae lander spent more than ten years riding aboard Rosetta before dropping onto Comet 67P on November 12, 2014, and almost nothing went to plan. A dead cold gas thruster, harpoons that never fired, and a momentum wheel that shut off too early sent the 100 kilogram probe bouncing a full kilometer into space, tumbling end over end, with only a six centimeter per second margin below escape velocity. Two hours later it came to rest wedged in a shadowed crevice named Abydos, tilted 30 degrees with one leg pointing at the sky.

This episode follows Philae’s story as a biography of a machine: the last minute target change from Comet Wirtanen to 67P, the shock absorbers engineered into its carbon fiber struts, the frantic 60 hour science campaign on a dying battery, and the surprise discoveries that came from failure. MUPUS could not hammer into the surface because the comet was rock hard sintered ice, and while the SD2 drill delivered nothing to the ovens, the COSAC and Ptolemy spectrometers still detected 16 organic compounds in ambient dust, four never before seen on a comet. We also cover the seven month hibernation, the brief June 2015 wake up, and the September 2016 Rosetta photograph that finally located the lander.

• Why the switch from Comet Wirtanen to the much larger 67P forced engineers to redesign Philae’s landing gear
• How a broken thruster, failed nitrocellulose harpoons, and a premature momentum wheel shutdown combined into a kilometer high bounce
• The 60 hour battery race in the Abydos crevice, where the lander received only 90 minutes of sunlight per 12.4 hour comet day
• How the MUPUS penetrator’s failure revealed comets are not fluffy snowballs but mechanically strong primitive ice
• The 16 organic molecules found in the dust, including acetamide with its peptide bond, and what they mean for the origins of life