Apollo 17

Apollo 17 was the eleventh and final crewed mission of NASA's Apollo program, marking the sixth and most recent time humans have walked on the Moon. Launched on December 7, 1972, the mission concluded on December 19, 1972, setting several records for crewed spaceflight, including the longest lunar landing, the largest lunar sample return, and the longest time spent in lunar orbit.

Background and Objectives

Apollo 17 was designated as a "J-class" mission, a classification that utilized extended hardware to allow for a longer stay on the lunar surface and a greater focus on scientific research. The primary objectives included geological surveying and sampling of the Taurus-Littrow valley, deploying the Apollo Lunar Surface Experiments Package (ALSEP), and conducting orbital science experiments. Additionally, Apollo 17 was the first and only Apollo mission to launch at night, a scheduling decision made to optimize the lighting conditions for the lunar landing site.

Crew

The spacecraft was crewed by three astronauts: Commander Eugene Cernan, Command Module Pilot Ronald Evans, and Lunar Module Pilot Harrison Schmitt. Schmitt, a trained geologist, was the first and only professional scientist to walk on the Moon. He was assigned to the crew in place of Joe Engle to maximize the scientific return of the final mission. Cernan and Schmitt descended to the lunar surface in the Lunar Module Challenger, while Evans remained in lunar orbit aboard the Command and Service Module America to conduct orbital observations and operate scientific instruments.

Mission Profile

Apollo 17 launched atop a Saturn V rocket from Kennedy Space Center Launch Complex 39A at 12:33 a.m. EST on December 7, 1972. The night launch provided a spectacular visual display visible across much of the southeastern United States. After a standard translunar injection and coast phase, the spacecraft entered lunar orbit on December 10.

Cernan and Schmitt successfully landed in the Taurus-Littrow valley on December 11. After spending three days conducting surface operations, they ascended in the Lunar Module to rendezvous and dock with Evans in the Command Module. The crew then initiated the trans-Earth injection, splashing down safely in the Pacific Ocean on December 19, 1972, where they were recovered by the USS Ticonderoga.

Lunar Surface Operations

The landing site, Taurus-Littrow, was selected for its unique geological features, offering the potential to yield samples of both ancient highland material and relatively young volcanic basalts. During their 75-hour stay on the surface, Cernan and Schmitt conducted three extravehicular activities (EVAs) totaling over 22 hours.

The astronauts utilized the Lunar Roving Vehicle (LRV) to travel a record distance of approximately 35.7 kilometers (22.2 miles) across the lunar terrain. They collected roughly 111 kilograms (245 pounds) of lunar rocks and regolith, the largest haul of any Apollo mission. Notable samples include "Troctolite 76535," which has provided crucial insights into the Moon's early magnetic field, and the "orange soil" discovered at Shorty Crater, which was later identified as volcanic glass beads formed by ancient lunar fire fountains.

Scientific Discoveries and Legacy

Beyond the geological samples, Apollo 17 deployed a comprehensive ALSEP array, which included a heat flow experiment, a lunar seismic profiling experiment, and a lunar atmospheric composition experiment. These instruments transmitted valuable data back to Earth for several years. During the transit to the Moon, the crew also captured the iconic "Blue Marble" photograph, one of the most widely distributed images in human history, showing a fully illuminated Earth against the blackness of space.

Apollo 17 remains a monumental milestone in space exploration. As the final mission of the Apollo era, it demonstrated the peak of 20th-century human spaceflight capabilities and left a profound scientific legacy that continues to inform planetary science today. Before leaving the lunar surface, Commander Eugene Cernan, the last human to step off the Moon, unveiled a plaque left on the landing gear of the Lunar Module, which read: "Here man completed his first explorations of the Moon, December 1972, A.D. May the spirit of peace in which we came be reflected in the lives of all mankind."