As we celebrate the 50th anniversary of Stanley Kubrick’s 2001: A Space Odyssey, some reflections on the most famous character in the film: HAL, the on-board computer.

This year marks the 50th anniversary of the premiere of the film 2001: A Space Odyssey. Among the things that makes this film stand out for sci-fi fans is "HAL," the computer that runs the ship.

The breakout movie Hidden Figures tells the story of three African American women who worked as mathematicians at NASA. The story sheds light on the significant contributions of the three women—Katherine Johnson, Dorothy Vaughan, and Mary Jackson—but also the broader impact that women had behind the scenes at NASA. Johnson, Vaughan, and Jackson all began their careers at the National Advisory Committee for Aeronautics (NACA)—which later became NASA—working as “computers.” Computers were not what we think of them today. They were people, primarily women, who reduced or analyzed data using mechanical calculators—we’ve previously explored the role of computers in astronomy.

As the Apollo program took form in the early 1960s, NASA engineers always kept the safety of their astronauts at the fore in light of the enormous risks they knew were inherent in the goal of landing on the Moon and returning safely. Wherever possible, they designed backup systems so that if a primary system failed the crew would still have the means to return home safely. Sometimes creating a backup was not always practical. For example, the Service Module’s engine needed to fire while the crew was behind the Moon to place them in a trajectory that would return them to Earth. There was no practical backup if the engine failed. But even in that instance a plan was worked out to use the Lunar Module’s (LM) engine as a backup. D