On December 13, 1972, at 11:40:56 p.m. CST, Apollo 17 Commander Eugene A. Cernan became the last person to leave a footprint in the lunar soil. Four days later, after a 500,000-mile round trip, Cernan and crewmates Harrison "Jack" Schmitt and Ronald E. Evans splashed down in the Pacific Ocean, concluding the Apollo lunar program. Supported by more than 400,000 workers and 25,000 companies, the program sent 12 astronauts to walk on the Moon during six missions between 1969 and 1972. Their goal was to study and explore the Moon, and the Moon landings came to represent a technological achievement of immense scale as well as a shared national purpose. Since Apollo 17 left the Moon in 1972, no human exploration beyond Earth orbit has been attempted.