While the astronauts flew in space, Mission Control closely monitored from the ground. Coordinating with radio stations in California, Spain and Australia to provide 24-hour communications and telemetry data during the Apollo missions, “Houston”—as the astronauts called Mission Control—is almost as famous as any of the people who flew to the moon, and Gene Kranz was one of the most influential people in that room.
In his memoir, Failure Is Not an Option: Mission Control From Mercury to Apollo 13 and Beyond, Kranz describes his role during many of the most famous spaceflights in history. Chris Kraft, NASA’s first lead flight director, assigned Kranz a job as a Mission Control procedures officer, and Kranz assisted with the first launches of Alan Shepard (the first American in space) and John Glenn (the first American to orbit the Earth). During the Gemini program, as the space race was kicking in to full swing, Kraft came to rely on Kranz as a flight director, and during Gemini 4, "He just said, 'You're in charge,' and walked out."
Kranz later took over as lead flight director, a role he maintained through Apollo 11 as Armstrong and Aldrin touched down on the moon. He was also the lead flight director for Apollo 13, guiding the crippled spacecraft back to Earth safely after an oxygen tank exploded during the flight to the moon, forcing the crew to swing around the moon and return to Earth without a lunar landing. During these moments and more, as the astronauts made history and escaped disaster, Kranz was in charge of Mission Control on the ground.