Eugene Cernan: The Commander of Apollo 17 in 1972; he was the last astronaut to walk on the moon.

He was also the second person to walk in space in 1966 as the pilot on Gemini 9 (Ed White was the first to walk in space).

He retired from the Navy in 1976 and later started an aerospace consulting company in Houston.

In 1999, he co-authored The Last Man on the Moon with Don Davis. The book contains his memoirs of his career both with NASA and before. He has also been featured in space exploration documentaries, such as In the Shadow of the Moon, in which he stated: “Truth needs no defense” and “Nobody can take those footsteps I made on the surface of the moon away from me.” Cernan also contributed to the book of the same name.

On May 13, 2010, Cernan and Neil Armstrong testified before Congress in opposition to President Barack Obama’s cancellation of the Constellation program, initiated during the Bush administration as part of the Vision for Space Exploration to return humans to the Moon and later to Mars, but later deemed underfunded and unsustainable by the Augustine Commission in 2009. Age: 78.

Harrison Schmitt: He was the Lunar Module pilot for Apollo 17 and the only true scientist (a geologist) who walked on the Moon.

Schmitt claims to have taken the photograph of the Earth known as The Blue Marble, one of the most widely distributed photographic images in existence. (NASA officially credits the image to the entire Apollo 17 crew.)

While on the Moon’s surface, Schmitt collected the rock sample designated Troctolite 76535, which has been called “without doubt the most interesting sample returned from the Moon”. Among other distinctions, it is the central piece of evidence suggesting that the Moon once possessed an active magnetic field.

As he returned to the Lunar Module before Cernan, Schmitt is the next-to-last person to have walked on the Moon’s surface. After the completion of Apollo 17, Schmitt played an active role in documenting the Apollo geologic results and also took on the task of organizing NASA’s Energy Program Office.

In August 1975, Schmitt resigned from NASA to seek election as a Republican to the United States Senate representing New Mexico. He served one term and sought a second term in 1982, but due to a deep recession and concerns that he wasn’t paying attention to local matters, he was defeated in a re-election. Following his Senate term, Schmitt has been a consultant in business, geology, space, and public policy.

Schmitt does not agree with prevailing wisdom on climate change. He has said that “the CO2 scare is a red herring”, that the “global warming scare is being used as a political tool to increase government control over American lives, incomes and decision-making,” and that scientists who might otherwise challenge prevailing views on climate change dare not do so for fear of losing funding. Schmitt wrote a book entitled Return to the Moon: Exploration, Enterprise, and Energy in the Human Settlement of Space in 2006. Age: 77.

Ronald Evans: He served as a captain in the United States Navy and became as astronaut in 1966.

His first and only space flight was as Command Module pilot of Apollo 17. On the way back to Earth, Evans completed a one-hour, six-minute extravehicular activity, successfully retrieving three camera cassettes and completing a personal inspection of the equipment bay area. He logged 301 hours, 51 minutes in space; 1 hour, 6 minutes of which were spent in extravehicular activity. He holds the record of more time spent in lunar orbit: six days and four hours (148 hours).

Evans retired from the US Navy on April 30, 1976, with 21 years of service, and remained active as a NASA astronaut involved in the development of NASA’s Space Shuttle Program. He served as a member of the operations and training group, within the astronaut office, responsible for launch and ascent phases of the Shuttle flight program. He retired from NASA in 1977 to pursue a career in the coal industry. He died of a heart attack on April 7, 1990.