The crew of Apollo 17 addresses a joint session of Congress after the completion of the final Apollo moon landing mission.
Apollo 17 (December 7 – 19, 1972) was the final mission of NASA's Apollo program, the most recent time humans have set foot on the Moon or traveled beyond low Earth orbit. Commander Eugene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, while Command Module Pilot Ronald Evans orbited above. Schmitt was the only professional geologist to land on the Moon, selected in place of Joe Engle with NASA under pressure to send a scientist to the Moon. The mission's heavy emphasis on science meant the inclusion of a number of new experiments, including a biological experiment containing five mice carried in the command module.
Mission planners considered two primary goals in selecting the landing site: to sample lunar highland material older than Mare Imbrium and to investigate the possibility of relatively recent volcanic activity. They thus selected Taurus–Littrow, where formations that had been viewed and pictured from orbit were thought to be volcanic in nature. Since all three crew members had backed up previous Apollo lunar missions, they were familiar with the Apollo spacecraft and had more time for geology training.
Launched at 12:33 a.m. Eastern Standard Time (EST) on December 7, 1972, after the only launch-pad delay in the Apollo program caused by a hardware problem, Apollo 17 was a "J-type" mission that included three days on the lunar surface, extended scientific capability, and the use of the third Lunar Roving Vehicle (LRV). Cernan and Schmitt landed in the Taurus–Littrow valley and completed three moonwalks, taking lunar samples and deploying scientific instruments. Orange soil was discovered at Shorty crater, and proved to be volcanic in origin, although from early in the Moon's history. Evans remained in lunar orbit in the command and service module (CSM), taking scientific measurements and photographs. The spacecraft returned to Earth on December 19.
The mission broke several records for crewed spaceflight, including the longest crewed lunar landing mission (12 days 14 hours), greatest distance from a spacecraft during an extravehicular activity of any type (7.6 kilometers (4.7 mi), a record which still stands), longest total lunar surface extravehicular activities (22 hours 4 minutes), largest lunar sample return (approximately 115 kg or 254 lb), longest time in lunar orbit (6 days 4 hours), and most lunar orbits (75).