Commander Eugene Cernan and geologist Harrison Schmitt landed Challenger in a mountain-ringed valley chosen for its promise of diverse rock samples, while Ronald Evans orbited above in the command module. Schmitt, the only professional scientist to walk on the Moon, helped the pair collect 110 kilograms of rock and soil, including the famous orange volcanic glass, during three moonwalks over the following three days.
NASA picked Taurus-Littrow specifically because it offered both ancient highland material and evidence of more recent volcanic activity, a geologist's dream landing site. Schmitt's academic training paid off almost immediately: he spotted orange soil, later confirmed to be tiny beads of volcanic glass roughly 3.7 billion years old, sprayed across the valley floor by a long-extinct lunar fire fountain.
Cernan and Schmitt spent over 22 hours outside the spacecraft across three excursions, driving the lunar rover more than 30 kilometers total and deploying a suite of scientific instruments. Budget cuts had already killed Apollo 18, 19, and 20, so mission planners knew, even as they packed the descent stage, that this landing carried extra weight.
When Cernan climbed the ladder for the last time on December 14, he spoke words meant to last: 'We leave as we came, and, God willing, as we shall return, with peace and hope for all mankind.' No human being has set foot beyond low Earth orbit since. The three astronauts returned to Earth on December 19, closing out the Apollo program after eleven crewed missions and six landings.
Key people: Eugene Cernan, Harrison Schmitt