TIME Studios is producing the Netflix documentary series Countdown: Inspiration 4 Mission to Space, starting Sept. 6.

It’s been 52 years since the artist Jeff Gates made a reservation to go to the Moon. Like many who gathered around their TV sets to watch the first lunar landing on July 20, 1969, Gates—then a 20-year-old college student home for summer vacation—walked outside immediately afterward and looked skyward.

“I kept saying, ‘there are human beings on that Moon!,’ says Gates, now 72. “It was unbelievable, and I wasn’t quite sure what to do with that feeling. But I wanted to be a part of that shared moment of exhilaration and amazement … It’s just human nature to want to be part of that.”

Gates, a longtime reader of sci-fi and fantasy books, had seen some media coverage of Pan Am’s First Moon Flights Club, a marketing stunt from the now-defunct airline offering lunar passage by the year 2000. He called an agent at the airline and made a reservation for himself and “Mrs. Gates,” the wife he assumed he would have by then. His membership card, numbered 1,043 out of 93,000 such tickets issued between 1968 and 1971, has been in the collection of the Smithsonian’s National Air and Space Museum in Washington, D.C. since 2016.

This Pan Am "First Moon Flights" Club card, number 1043, was issued by the airline to Jeffrey Gates in the late 1960s. Gates acquired the card (as well as reservations for himself and his wife-of-the-future) when he was 20 years old. (Courtesy Smithsonian's National Air and Space Museum)
This Pan Am "First Moon Flights" Club card, number 1043, was issued by the airline to Jeffrey Gates in the late 1960s. Gates acquired the card (as well as reservations for himself and his wife-of-the-future) when he was 20 years old.
Courtesy Smithsonian's National Air and Space Museum

Like so many other hopeful would-be astronauts, Gates never got his chance to go to space. In fact, after booking his flight, he didn’t think much about the card at all until the space shuttle Challenger disaster in 1986. “What I did realize was we are not at the point where commercial space travel is going to be normalized anytime soon,” he says of that incident, which killed all seven aboard. But five decades after booking his never-used tickets, Gates—and his wife, Susie, who he married in 1991—has been watching in recent weeks as a series of civilian space missions are bringing his dreams ever closer to reality. Richard Branson’s Virgin Galactic flight and Jeff Bezos’s Blue Origin launch made headlines with their short suborbital jaunts, while the upcoming Inspiration4 mission plans to put an all-civilian crew into orbit for the first time.

The Branson, Bezos and Inspiration4 missions, while historic in their own rights, also represent new landmarks in a long-evolving effort to open space up to non-professionals. Indeed, private citizens have been joining astronauts in space for nearly four decades, a mixture of experts picked to handle specialized equipment being launched into space, members of Congress who had power over NASA’s budget, people selected as publicity stunts or in the name of diplomacy, and billionaires who could afford outrageous sums for the privilege to strap themselves into a Russian Soyuz rocket.

To whom the honor of “first civilian in space” belongs depends on your point of view. Back in the heyday of the Cold War and the 1960s Space Race, NASA recruited its astronauts almost exclusively from the ranks of military test pilots. Diversity at that point meant how many candidates were drawn from the Air Force versus the Navy (with some Marine pilots thrown in). So when Neil Armstrong was selected for the astronaut program in 1962, the choice was notable. Armstrong had served as a Naval aviator in Korea, returned to Purdue to complete his degree, and then joined NASA’s predecessor agency as a test pilot. Given that Armstrong was no longer in the military and that NASA was a civilian agency, he was dubbed the first civilian astronaut to fly at the time of his 1966 Gemini 8 mission. Of course, Armstrong’s flight test experience and NASA training made the distinction mainly technical.

In the mid-1980s, NASA began picking “payload specialists”—people with specialized experience on a particular piece of hardware—to join space shuttle missions. While most in the space community now agree that these specialists deserve to be called “astronauts” as much as anyone else who flew on the shuttle, they were among the first people to travel to space who weren’t on a government payroll. McDonnell Douglas test engineer Charlie Walker, who flew on three different shuttle missions between 1984 and 1985, was the first such specialist, and ran an experiment designed to help pharmaceutical research.

Politicians who held sway over the U.S. space program soon followed. In 1985, Senator Jake Garn (R-UT), then chair of the subcommittee charged with overseeing NASA’s budget, joked that the agency wouldn’t get “another cent” unless they let him go to space. NASA granted his wish, giving him a spot aboard the space shuttle Discovery’s fourth flight in 1985. In its coverage, TIME noted that the decision to send Garn to space came a few months after then-U.S. President Ronald Reagan announced that the first truly private citizen in space would be a teacher. “When the shuttle lifts off, all of America will be reminded of the crucial role teachers and education play in the life of our nation,” Reagan said in a 1984 speech to schoolworkers. “I can’t think of a better lesson for our children and our country.” When TIME asked Garn whether he was taking a spot away from a teacher (in an April 22, 1985 story headlined “Jake Skywalker”), Garn characterized his request as part of his oversight function. “I am a public official,” he said. “I am concerned. I even flew the B-1 bomber years ago, to decide whether that was something I ought to vote for or not, and I’ve driven the M-1 tank for the same reason.” A Salt Lake City newspaper poll showed 69% of participants supported sending Garn—who was up for re-election the following year—to space. (Bill Nelson, who this year became NASA administrator, similarly flew on a shuttle mission in 1986, when he was a congressperson.)

In June 1985, NASA invited another public figure on a shuttle mission, this time a foreign dignitary: the then-28-year-old Sultan ibn Salman Al Saud of Saudi Arabia, who went up to photograph the launch of a Saudi communications satellite. His trip marked a number of firsts: he was the first Saudi, the first Arab, the first Muslim and the first member of a royal family to travel into space. He was also the youngest space shuttle passenger to date. His selection, says Margaret Weitekamp, chair of the National Air and Space Museum’s space history division, also had a diplomatic angle. “The flight of the Saudi prince was a way of demonstrating, materially, some loyalty to a political partner and technological partner in this project,” she says. “The Saudis were paying NASA to launch the satellites onboard their launch vehicle … and so then they got the chance to have a payload specialist [on board].”

Reagan’s earlier promise to send a teacher to space materialized in the mid-1980s as the Space Flight Participant program, an effort to send private citizens into space who could tell great stories or inspire others when they returned, like journalists and teachers. Christa McAuliffe, a New Hampshire social studies educator, was selected as the first teacher in the program. “I watched the Space Age being born and I would like to participate,” she wrote in her application.

The Participant program “was all about communicating,” says former Alan Ladwig, a former NASA official who once ran the initiative. “Part of that was because it was felt that astronauts were not the greatest communicators. Some of them were, but there was a feeling that we want to hear more about what space is like except that it’s ‘neat.’ [The goal] was trying to get a more unfiltered look. Tell us what you really felt and why this is all important.”

The larger goal, says Ladwig, was to inspire people to pursue what are now called STEM careers—science, technology, engineering and math—to firm up a talent pipeline upon which NASA could draw. “My hope was this would inspire students to want to study science and math,” he says. “Not enough students were getting into science and math, especially young women, and even today that’s getting better, but it’s still not where it should be.” But the program came to a tragic halt when the Challenger exploded shortly after liftoff on Jan. 28, 1986, killing all those aboard—including McAuliffe.

Over the next decade or so, the Russians picked up the civilian space travel ball where the Americans had dropped it. Throughout the 1990s, private citizens like Japanese journalist Toyohiro Akiyama and British chemist Helen Sharman blasted off aboard Soyuz rockets for Russia’s Mir space station, which was deorbited in 2001, a few years after the International Space Station (ISS) was launched. Akiyama was sent as a promotional stunt for his television station, while Sharman was sponsored by a consortium of British companies seeking to put the first Briton in space.

That the turn-of-the-century dot-com era created a bevy of new millionaires and billionaires with money to burn was opportune for Russia’s space program, which at the time was hemorrhaging cash. The “Russian program badly needed money, and was willing to fly paying customers,” says John Logsdon, founder of George Washington University’s Space Policy Institute. Space Adventures, a Virginia-based space tourism company that launched in 1998, brokered seats aboard the Soyuz for those with enough money to make the trip. First among them was Dennis Tito, founder of investment firm Wilshire Associates, who reportedly paid $20 million in 2001 dollars for a trip to the ISS, thus becoming the world’s first true space tourist. Tito’s trip, says Ladwig, “got the dreamers excited” about private space travel again.

Space Adventures has since launched six other space tourists to the ISS, including telecom entrepreneur Anousheh Ansari (the first female space tourist, the first of Iranian descent and the first Muslim woman in space, and who now heads the X-Prize Foundation), video game developer Richard Garriott (the first son of an astronaut to pay his own way) and Charles Simonyi (a tech billionaire who helped create Microsoft Word and Excel and the only space tourist to make repeat trips, in 2007 and 2009).

Now, with the rise of U.S.-based private space companies, like Branson’s Virgin Galactic, Bezos’s Blue Origin and Elon Musk’s SpaceX, prospective space tourists no longer need to travel to the remote desert steppe of Baikonur, Kazakhstan for a ride aboard a Russian rocket. It’s still early days for all three companies. But for civilians dreaming of a trip to the stars, their ship may come in—and blast off—soon enough. “Jeff Bezos, Richard Branson, Elon Musk, [they] should make good on my ticket to the Moon,” says Gates, whose wife Susie is game to join him. “That would be a great honeymoon,” she says.

TIME Studios is producing the Netflix documentary series Countdown: Inspiration 4 Mission to Space, starting Sept. 6.

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Write to Olivia B. Waxman at olivia.waxman@time.com.