David Scott: He was the Commander for the mission. Scott made his first flight into space as pilot of the Gemini 8 mission along with Neil Armstrong in March 1966.

Scott later spent ten days in orbit, in March 1969, as Command Module Pilot aboard Apollo 9, his second spaceflight. He was the last American to fly solo in Earth orbit.

Scott made his third and final flight into space as commander of the Apollo 15 mission, the fourth human lunar landing, becoming the seventh person to walk on the Moon and the first person to drive on the Moon in the Lunar Rover.

After the return of Apollo 15 to Earth, it was discovered that, without authority, Scott, with the knowledge of his crew, had taken 398 commemorative postal covers to the moon of which a hundred were then sold to a German stamp dealer. While not illegal, NASA weren't happy and made an example of Scott and his crew. None of them ever flew in space again. The stamp story is detailed here.

In 1975 Scott became the Center Director of NASA's Flight Research Center, a position he held until October 30, 1977. In 2000, he was briefly engaged to British television newscaster Anna Ford.

He's acted as a consultant on TV series such as From The Earth To The Moon and the BBC's Space Odyssey: Voyage To The Planets.

In 2004, he and former Soviet cosmonaut Alexei Leonov began work on a dual biography / history of the "Space Race" between the United States and the Soviet Union. The book, Two Sides of the Moon: Our Story of the Cold War Space Race was published in 2006.

Scott is one of the astronauts featured in the book and superb documentary In the Shadow of the Moon, and was instrumental in helping to get the film off the ground. Age: 80.

James Irwin: Lunar Module pilot aboard Apollo 15. In 1961, his plane crashed on a routine training mission - a student pilot he was training crashed the plane they were flying. They both survived, but Irwin suffered compound fractures, amnesia, and nearly lost a leg.

Apollo 15 was more science-based than previous missions, which meant that the astronauts received intensive geological training to meet the demanding nature of the mission. This extra training is credited with allowing them to make one of the most important discoveries of the Apollo era - the Genesis Rock.

A patch cut by Irwin from the backpack abandoned on the Moon during the Apollo 15 mission was auctioned at Christie's in 2001 for $310,500 in a consignment of material from Irwin's estate that garnered "a combined $500,000".

While exerting himself on the Moon, Irwin's flight surgeons found that his heart had developed bigeminy. Dr. Charles Berry stated at the time: "It's serious, if he were on Earth. I'd have him in ICU being treated for a heart attack." The 100% oxygen atmosphere in the Command Module cabin and the zero-g environment probably saved his life.

Irwin is also known for his Christian work. He left NASA and retired from the Air Force with the rank of Colonel in 1972 and founded the High Flight Foundation, spending his last 20 years as a "Goodwill Ambassador for the Prince of Peace", stating that "Jesus walking on the earth is more important than man walking on the moon". He frequently spoke about how his experiences in space had made the presence of God even more real to him than before. Beginning in 1973, Irwin led several expeditions to Mount Ararat, Turkey in search of the remains of Noah's Ark. Irwin died on August 8, 1991, as the result of a heart attack.

Al Worden: He was the Command Module pilot on Apollo 15. Worden has been listed in the Guinness Book of World Records as the "Most isolated human being" during his time alone in the command module Endeavour. When the orbiting command module was at its greatest distance from Scott and Irwin in the Falcon, Worden was 2,235 miles away from any other human beings.

During 1972-1973, Worden was Senior Aerospace Scientist at the NASA Ames Research Center, and from 1973 to 1975, he was chief of the Systems Study Division at Ames. Between 1972 and 1975.

After retirement from NASA and active duty in 1975, Worden became president of Maris Worden Aerospace, Inc., and then became staff vice-president of BG Goodrich Aerospace. He served as chairman of the Astronaut Scholarship Foundation until 2011, providing scholarships to exceptional science and engineering students.

Worden is the last of the Apollo astronauts to participate in the Kennedy Space Center's Encounter with an Astronaut program in which the public can attend a lecture by, ask questions of, and even dine with an astronaut. In 2011, Worden's memoir Falling To Earth made the top 12 of the LA Times Bestseller list. Age: 80.