Americans watched with wonder as Buzz Aldrin bounded across the surface of the moon on July 20, 1969.
But back at Mission Control, Sonny Reihm's jaw tightened.
"Make that silly bastard get back in the LM!" he recalled thinking, referring to the Lunar Module, the first manned craft to land on the moon.
While most of the 400,000 or so people who helped carry out the Apollo 11 mission were part of NASA or the aerospace industry, Reihm worked with a company best known for making bras and girdles.
But the International Latex Corporation (ILC), then parent company to Playtex, was charged with creating one of the most vital pieces of the mission: a spacesuit fit for the moon.
Though Reihm had spent nearly a decade with his team perfecting every stitch of the suits as project manager, Aldrin and Neil Armstrong's moon walk was the first full test of their design and craftsmanship.
Naturally, he didn't want the Apollo astronauts tempting the fates by staying outside any longer than necessary.
"We're successful. We can declare a success. We can declare it right now, but they're not inside!" he thought from the control room in Houston. "I don't care how many craters Buzz wants to look at, get him back inside!"
And Reihm had reason for concern: The moon is not so harmless as astronauts have come to make it seem by running, jumping, and even golfing on its surface. Extreme temperatures, corrosive dust and unfiltered solar radiation are just a few threats that would make a poorly-planned visit more quixotic than quotidian.
For its Apollo 11 astronauts to survive, NASA needed a suit that could serve as a self-contained human environment hundreds of thousands of miles from Earth, all while being flexible and tough enough to allow Armstrong and Aldrin to work with agility.
The maker of Playtex garments and consumer goods like diapers may have seemed an unlikely contender to build NASA's suits, but ILC had developed novel ways of creating and blending flexible textiles and rubbers over the years, and had some experience creating pressure suits for high-altitude military pilots.
"The background for the basic fabric of a spacesuit was there in Playtex," Reihm said. "They had the technology."
The company also had a small team of forward-looking engineers with a passion for space exploration. They had been quietly designing a suit since 1958, anticipating John F. Kennedy's famous "We choose to go to the moon" speech by some four years.
Despite their drive and unique technology, the scrappy ILC team was up against weighty competitors like B.F. Goodrich and the David Clark Company, which had already built spacesuits for the Mercury and Gemini missions, respectively. ILC had competed against the former for the Mercury contract, but lost.
As Reihm tells it, while other companies merely submitted their ideas to NASA on paper, his team outmaneuvered them by adding a video of their design in action. The proof-of-concept footage showed a man in full kit sprinting across a football field to catch passes.
"When they saw that, they go, 'I don't know who did this, but this is the suit we want,'" he said.
In 1962, NASA announced ILC would build the suits for its astronauts, with another contractor responsible for the life support system that would be worn as a backpack. After several more years of trial and error, problems identified and overcome, the Apollo 11 spacesuit was ready.
The final version had more than 20 layers of integrated plastics, metals and other materials, including an outer shell made using a mix of glass and Teflon to help shield from micrometeoroids. The design solved other critical challenges with a liquid-cooling garment to regulate body temperature and convoluted joints -- think of a bendy straw -- to allow mobility while maintaining a pressurized seal inside the suit.
"It was a work of art," Reihm said.
But it had yet to be truly tested.
Back at Mission Control on that historic summer day in '69, Reihm watched his work of art closely. While he was confident in the suit's design, the possibility of unknown and unaccounted for dangers kept him on edge until Armstrong and Aldrin were back inside the Lunar Module.
Once it was clear the astronauts had triumphed, Reihm's apprehension gave way to elation.
"I was just delighted to see them finish, let's put it that way," he said.
The astronauts had no complaints with their spacesuits, Reihm said, and despite being caked in the moon's harsh dust, an inspection back on Earth showed no discernible wear.
"Suit held up perfect," he said.
ILC deepened its relationship with NASA after Apollo 11, and has since put rovers on Mars, developed inflatable space habitats for planetary exploration, and built the suits worn on the International Space Station by today's astronauts.
ABC News' Nate Luna and Christine Theodorou contributed to this report.