Morgan found out many years later that her supervisor had fought hard to get her into the room. He had told his superiors that he needed her there. Morgan was the best they had.

Three years before the moon landing, Morgan sat down at a console to conduct some tests. She was about to plug in her headset when she felt a hand whack her on the back. “We don’t have women in here,” the man behind her said.

Morgan called the director of her team, Karl Sendler, who had ordered the tests. Sendler was one of the engineers who had come to the United States from Germany with Wernher von Braun, whose Nazi record was hidden from the public after World War II, to help build the Saturn V rocket that launched the Apollo crew. He told Morgan to ignore the guy and get to work, so she did. Later that afternoon, Rocco Petrone, the manager of the Apollo program, stopped by. “He sort of gently tapped me on the shoulder and he said, ‘JoAnn, you’re always welcome,’” Morgan told me recently. Her boss, she assumes, had made some calls.

It was difficult for her to feel welcome at Kennedy, though. “It was 100 percent men every place I went,” Morgan said. Many were startled when the engineer “J. Morgan” walked into the room and turned out not to be a man. Most got over the surprise and worked amiably with her. Some didn’t. Morgan made friends with the secretaries and the librarian at the nearby Air Force base, a Filipino woman with a master’s degree, a rarity in her own right. When male employees made crass comments, Morgan confided in the center’s sole female lawyer.

The Florida coast was its own solar system, with Cape Canaveral at its center, and many other women were there. Thousands of workers flocked to the area, bringing their families with them. Their lives, professional and social, gravitated around the space effort. The majority of women at Kennedy and other NASA centers in the 1950s and 1960s worked—or started out—as administrative assistants, typists, and, like Katherine Johnson, Dorothy Vaughan, and the other women whose stories were told in Hidden Figures, human computers calculating orbital mechanics.

Read: “Hidden Figures” and the appeal of math in an age of inequality

The paucity of women was more apparent in technical fields such as engineering, where Morgan began her career. She joined the American space effort a decade before the Apollo 11 launch, as an intern right out of high school. NASA didn’t exist yet. Like most high-school kids in central Florida at the time, Morgan liked to go down to the beach at night to watch the Army launch rockets into the sky from nearby Cape Canaveral—they produced a spectacular light show if they blew up. Morgan watched the launch of Explorer 1, the first American satellite to reach space, and she remembers the astonishment she felt, learning that the satellite’s instruments had discovered bands of hazardous radiation curling around Earth. She marveled at the thought of sending something into space that could tell you about the world. “It was like a door opened in my mind,” Morgan said.