Apollo 17

Apollo 17, which took place from December 7 to December 19, 1972, stands as the eleventh and conclusive mission of NASA's ambitious Apollo program. It was the sixth and most recent instance of humans setting foot on the Moon, bringing an era of lunar exploration to a close. The crew comprised Commander Gene Cernan, Lunar Module Pilot Harrison Schmitt, and Command Module Pilot Ronald Evans.

Schmitt's inclusion was particularly noteworthy; as a professional geologist, he was the sole scientist to land on the Moon, a decision influenced by a desire to prioritize scientific objectives. This mission's strong scientific mandate led to the integration of novel experiments, including a biological study involving five mice housed within the command module, offering insights into the physiological effects of space travel.

The selection of the Taurus-Littrow valley as the landing site for Apollo 17 was a deliberate strategic decision driven by two primary scientific objectives. Firstly, planners aimed to acquire lunar highland material, believed to be significantly older than samples retrieved from the Mare Imbrium region during earlier missions, thus providing a deeper look into the Moon's early history. Secondly, the site was chosen to investigate the possibility of relatively recent volcanic activity.

Orbital observations and imagery had revealed formations within Taurus-Littrow that were theorized to be volcanic in origin. The crew's extensive experience, having served as backups on previous Apollo lunar missions, meant they possessed a deep familiarity with the spacecraft systems and had dedicated more time to specialized geological training, enhancing their capacity for scientific data collection and sample analysis.

Apollo 17 was classified as a 'J-type' mission, a designation signifying expanded scientific capabilities beyond earlier Apollo flights. These missions featured extended stays on the lunar surface, typically three days, and incorporated advanced scientific instruments. A key element of Apollo 17 was the deployment and utilization of the third Lunar Roving Vehicle (LRV).

This electric, four-wheeled vehicle dramatically increased the astronauts' range and efficiency, allowing them to cover greater distances during their three meticulously planned moonwalks. Commander Cernan and Dr. Schmitt explored the Taurus-Littrow valley, collecting a diverse array of lunar samples and deploying sophisticated scientific instruments designed to study the Moon's environment.

The discovery of bright orange soil near Shorty crater was a significant find, later confirmed to be volcanic in origin, offering tangible evidence of the Moon's geological past.

The Apollo 17 mission concluded by setting multiple records for crewed spaceflight, solidifying its place as a landmark achievement. It holds the record for the longest crewed lunar landing mission, spanning 12 days, 14 hours, and 30 minutes. The mission also recorded the greatest distance from a spacecraft during an extravehicular activity, with astronauts venturing 7.6 kilometers (4.7 miles) away.

The total time spent on the lunar surface reached an impressive 75 hours, with cumulative extravehicular activity time totaling 22 hours and 4 minutes across three moonwalks. Furthermore, Apollo 17 achieved the largest lunar sample return, bringing back approximately 115 kilograms (254 pounds) of lunar material for scientific study. The mission also logged the longest duration in lunar orbit, 6 days and 4 hours, during which 75 orbits were completed.

These records underscore the mission's success and its profound contribution to our understanding of the Moon.