Apollo 17 entered lunar orbit on Dec. 10, 1972. Astronauts Eugene A. Cernan and Jack Schmitt, the first trained geologist to travel to the Moon,𓄧 brought Challenger to a soft-landing at the Taurus-Littrow landing site and conducted three surface excursions totaling 22 hours, driving the third Lunar Roving Vehicle for 22.2 miles. They deployed a set of instruments that operated long after they departed and collected 254 pounds of rock and soil samples. During this time, Evans conducted observations of the lunar surface from orbit. Apollo 17 was the sixth and, so far, final crewed lunar landing. The mission was also the longest, lasting in total 12 days and 14 hours, with 75 hours spent on the lunar surface.