On the eve of the 50th Anniversary of the Apollo 11 moon landing in 2019, a group of former IBM employees met at a diner in Texas. The men and women once worked on NASA's Apollo program, writing the computer code that helped put astronauts on the moon. Today, in their late 70s and early 80s, they look back with pride—and astonishment—at their accomplishment. At their usual table, in front of piles of Cajun food, we meet Homer Ahr, who performed the computer calculations that kept the Apollo astronauts on course. There’s Sadie Stanley, who wrote the code that allowed radar stations to track the spacecraft. And there’s Tommy Steele, who built the software that governed the Saturn 5 rockets. Together, they did more than deliver man to the moon—they forged friendships that have lasted a lifetime. Now they’re stepping out of the shadows for the first time.