Michael Collins, the U.S. astronaut who in 1969 experienced an extreme of human solitude by orbiting Earth’s moon by himself as his Apollo 11 crewmates were taking man’s first steps on it, has died. He was 90. He died Wednesday, according to NASA’s website. No cause was given. As pilot of the command module Columbia, Collins kept a 28-hour vigil in orbit 60-plus miles from the moon’s surface as Neil Armstrong and Edwin ‘Buzz’ Aldrin descended in the lunar module Eagle, landed and explored the moon’s surface. Before Collins, the only men to orbit the moon, and to experience the periodic communications blackout that accompanies it, were the three U.S. astronauts aboard Apollo 8, whose December 1968 mission had set the stage for a moon landing. But those three -- Frank Borman, James Lovell and William Anders -- had each other as company as they laid eyes on the far side of the moon and lost sight of the pale blue sphere known as Earth. Collins was the first to do it alone, and while the mechanics of the moon landing dominated discussion of Apollo 11, the potential psychological toll on Collins was among NASA’s concerns. “Not since Adam has a human known such solitude as Mike Collins is experiencing during the 47 minutes of each lunar revolution, when he is behind the moon with no one to talk to except his tape recorder,” NASA public affairs officer Douglas K. Ward said on July 21, 1969, the second day of Armstrong and Aldrin’s journey to the moon surface. At a press conference two weeks before liftoff, Collins had been asked a version of the question he’d face often: How would it feel to get so close to the moon without setting foot on it? “I’m going 99.9 percent of the way there,” he replied, “and that suits me just fine.” In his 1974 memoir, “Carrying the Fire,” Collins said he enjoyed his time alone in space. “I don’t mean to deny a feeling of solitude,” he wrote. “It is there, reinforced by the fact that radio contact with the Earth abruptly cuts off at the instant I disappear behind the moon. I am alone now, truly alone, and absolutely isolated from any known life. I am it. If a count were taken, the score would be 3 billion plus two over on the other side of the moon, and one plus God-knows-what on this side.” He said he felt not fear, or loneliness, but “awareness, anticipation, satisfaction, confidence, almost exultation.” After the mission, Collins received a letter from Charles Lindbergh, the famed aviator who had been the first to fly solo across the Atlantic Ocean. Lindbergh wrote that while he had followed Armstrong and Aldrin’s walks on the moon with great interest, “it seems to me that you had an experience of in some ways greater profundity. You have experienced an aloneness unknown to man before.” Acting NASA Administrator Steve Jurczyk said Wednesday, “Today the nation lost a true pioneer and lifelong advocate for exploration.” Collins was born on Oct. 31, 1930, in Rome, the son of a U.S. Army general, James Collins, whose job as a State Department military attache gave the family five different homes by the time Collins was 10. He graduated from St. Albans School in Washington and, in 1952, from the U.S. Military Academy at West Point. As a lieutenant colonel in the Air Force, he tested jet fighters and other aircraft at Edwards Air Force Base in California. Selected in October 1963 as part of NASA’s third group of astronauts, Collins was the pilot for Gemini X, a three-day mission in July 1966 mission that advanced NASA’s capabilities at rendezvous and docking and included a 90-minute spacewalk. In 1968 he underwent surgery to repair a herniated cervical disc, forcing his removal from the crew of Apollo 9. Just after Collins was restored to flight status, Armstrong and Deke Slayton, the director of flight crew operations, chose him to man Apollo 11’s command module. Even in training, “Mike Collins had it tougher” than Armstrong and Aldrin, Slayton wrote in his autobiography. “His training pretty much required him to be alone. If something went wrong, he didn’t have anybody else to blame or complain to.” Subscribe to our YouTube channel: https://bit.ly/2TwO8Gm Bloomberg Quicktake brings you live global news and original shows spanning business, technology, politics and culture. Make sense of the stories changing your business and your world. To watch complete coverage on Bloomberg Quicktake 24/7, visit http://www.bloomberg.com/qt/live, or watch on Apple TV, Roku, Samsung Smart TV, Fire TV and Android TV on the Bloomberg app. Have a story to tell? Fill out this survey for a chance to have it featured on Bloomberg Quicktake: https://cor.us/surveys/27AF30 Connect with us on… YouTube: https://www.youtube.com/user/Bloomberg Breaking News on YouTube: https://www.youtube.com/c/BloombergQuickTakeNews Twitter: https://twitter.com/quicktake Facebook: https://www.facebook.com/quicktake Instagram: https://www.instagram.com/quicktake