When former NASA astronaut Eileen Collins was asked to pilot the Space Shuttle in 1995 — the first woman to do so — she invited 13 women to her launch.

Those 13 women, known as the Mercury 13, were all female pilots from the 1960s who had undergone the same physical and psychological tests as the men NASA selected as astronauts. But because of their gender, they never made it to space. Now, a Netflix documentary premiering today tells the stories of these kick-ass women, and the prejudice they had to endure to pursue their dreams. Mercury 13 is a telling reminder of all the barriers women have had to face to be considered as equal in the spaceflight industry.

“I didn’t get here alone,” said Collins in a 1998 press conference. “There are so many women throughout this century that have gone before me and have taken to the skies, from the first barnstormers through the women military Air Force service pilots from WWII, the Mercury women from back in the early 1960s that went through all the tough medical testing. All these women have been my role models and my inspiration, and I couldn’t be here without them.”

The Mercury 13 was not an official NASA program. It was run by a NASA researcher, named William Randy Lovelace, who helped select the first seven astronauts for the US space program, called Project Mercury. Those astronauts were all “cookie cutter males,” as Sarah Ratley, one of the female pilots, calls them in the documentary. They were all white men; there was no diversity. “They were all exactly the same,” she says.

But Lovelace felt that women had to have a place in space — after all, the Soviet Union was interested in training female cosmonauts — and so in 1960, he began recruiting women to see how they’d fare in NASA’s endurance tests. The women performed just as well as the men, if not better, according to Lovelace’s daughter Jackie. But before they could conclude the screening, NASA canceled the program. And so, the first woman in space was not an American, but a Russian: Valentina Tereshkova, who in 1963 orbited the Earth 48 times.

Through historical footage and sit-down interviews with four of the women involved in the program, Mercury 13 tells a very compelling story. In one scene, 91-year-old Rhea Woltman, wearing a yellow jacket and hat, boasts that she could fly as well as Jerrie Cobb, the first female pilot picked for the astronaut tests. Their eyes light up when they talk about flying, or their dreams of floating in zero gravity. It makes some of the historical footage painful to watch, knowing how it all turned out.

In a TV interview from 1963, a male journalist asks Cobb whether she feels “there’s a need for women in space.” Her answer: “Well, it’s the same thing as, ‘Is there a need for men in space?’ I mean, if we’re going to send a human being into space, we should send the one most qualified. And in certain areas, women have to offer, in other areas men do. I think we ought to use both.”

In another interview, a male journalist asks Jane Hart, one of the female pilots, the mother of eight kids, and wife of a Michigan senator whether it’d be hard for a woman astronaut to also have a family. Her answer: “Well, I’ve accomplished the production of eight children and I’m in process of raising them, and I’ve still been able to acquire 2,000 hours of flying time and considerable aeronautical experience and also helped my husband in his campaigns and so forth. So, this indicated that I’ve been able to make constructive use of my time outside of having the children, and I don’t think the family life has been sacrificed one bit.”

Mercury 13 follows the story in chronological order, puncturing the personal narratives with the biggest space race milestones. Some questions, however, are left unanswered. It’s not exactly clear why Jacqueline Cochran, a famous pilot who had helped Lovelace launch the Mercury 13 program, later testified against it when the women brought their case to Congress in 1962. The documentary also doesn’t provide NASA’s take on why the Mercury 13 program was shut down; Gene Nora Jessen, one of the women pilots, claims that NASA said they had “no need for women astronauts,” while Jackie Lovelace Johnson, Lovelace’s daughter, says that the space agency “didn’t want this program, pure and simple.”

Had the Mercury 13 pilots made it to space, the documentary implies, women across all of society would have been empowered. Whether that’s true, it’s hard to say. (We had to wait until 1983 to have the first American woman in space.) But their determination and commitment did manage to inspire other women to pursue careers in spaceflight. Collins, the former NASA astronaut, is likely just one example. By telling their stories, Mercury 13 is trying to do the same.

The opening and closing sequences are definitely a source of inspiration. The documentary starts with a montage of men in NASA’s mission control, wearing ‘60s glasses and smoking cigars. At the end, a similar montage shows something different — what the Mercury 13 pilots never got to experience: women floating in zero gravity.