Charles M. Schulz Museum

It was 1969, and the race to the moon was accelerating. Authors Francis French and Colin Burgess write that "Apollo 8 had successfully tested the CM (Command Module) in lunar orbit, and the crew of Apollo 9 had run the LM (Lunar Module) through its paces in Earth orbit. This next mission would combine the hardware and software components with the skills, experience and techniques of hundreds of thousands of people to carry out the most complex mission to date; Apollo 10 would be the precursor flight--the last forerunner--to the greatest technological achievement in the history of space exploration. If successful the mission of Apollo 10 would set the stage for a manned landing on the moon." French & Burgess, "In the Shadow of the Moon".
Apollo 10 rolls out of the massive Vehicle Assembly Building, Kennedy Space Center. (March 11, 1969; NASA)
Eugene Cernan, John Young and Thomas Stafford.

Captain Cernan notes that "Apollo 10 would be a full-dress rehearsal and do everything but touch down on the lunar surface. Deke (Slayton) gave Neil Armstrong's crew the historic assignment of tackling the first landing attempt, with the understanding that it just might not happen that way. If the command spacecraft or the lunar module didn't work well enough on Apollo 10, the schedule could slip again for further testing by Apollo 11. Then Apollo 12, or perhaps even Apollo 13, would get the first crack at the landing. Nothing was certain at this point, except Apollo 10 wouldn't be bringing home any Moon rocks. Looking back from today's vantage point, it was a good decision. Instead of being disappointed, Tom (Stafford), John (Young) and I eagerly embraced our new roles as lunar pathfinders."

Captain Cernan and Snoopy (courtesy Charles M. Schulz Museum and Research Center).

As recalls in his best-selling book, "The Last Man on the Moon", Gene Cernan says " The image-conscious NASA public relations people who felt that "Gumdrop" and "Spider" weren't really serious enough names for the historic value of Apollo 9 were even more underwhelmed when we obtained permission from Peanuts cartoonist Charles Schulz to christen the CM "Charlie Brown" and call the LM "Snoopy". The PR-types lost this one big-time, for everybody on the planet knew the klutzy kid and his adventuresome beagle, and the names were embraced in a public relations bonanza. The intrepid, bubble-headed Snoopy, flying his doghouse to the Moon with a red scarf flapping at his neck, became a symbol of excellence, and before the hoopla quieted, that little dog's image was on decals, posters, dolls, kits, sweatshirts and buttons everywhere. The program had never seen anything like it."

Apollo 10 Command Module, "Charlie Brown" above the Moon.

THE MISSION: NASA's account of the Apollo 10 misson.

"Many people have asked me over the years if I was disappointed that Apollo 10 did not make the first Moon landing," observes Captain Cernan. "How could we have come so close and not actually taken those first steps. Would I liked to have taken a shot at it? You bet I would. However, we all believed in the importance of our mission because we knew Apollo 11 was going to need every scrap of information we could gather if it was to have a successful flight of its own.

"Really, how could I be disappointed after riding the Saturn V rocket, the mightiest missle ever built, into orbit and then a quarter-million-miles from Earth, seeing unbelievable sights, hanging around the Moon for three days, descending to within 47,000 feet of the lunar surface, flying back to my home planet and making a super high-speed reentry in a fireball to land in the Pacific? Anyway, I had an idea--- I planned to go back."

Captain Cernan was right. On Apollo 17, he became the Last Man on the Moon. In fact, as authors French and Burgess note, "All three of the Apollo 10 crew members would fly Apollo missions again". They add that "Tom Stafford considers Apollo 10 his greatest contribution to the space program. As Buzz Aldrin declares, because of the Apollo 10 mission 'the door was wide open for Apollo 11'"

WATCH: Apollo 10 launch here.

SEE: What it's like to experience "zero gravity"

EXPERIENCE: What Capt. Cernan saw above the moon here.

THE FUTURE: See video of Capt. Cernan talking about returning to the moon here.

See the Apollo 10 Command Module at the Science Museum in London.