IBM’s IU performed as promised. When one of the rocket’s eight engines failed in an early Saturn I flight, the IU adjusted the other seven engines to compensate for the change in thrust — saving the mission. Similarly, IBM’s IU would come to the rescue for Apollo 12 when the Saturn V rocket was twice struck by lightning. With communications capabilities down, the astronauts became temporarily unable to make contact with Mission Control or with their flight instruments in the command module. Just in time, the IU adjusted to maintain the rocket’s course.
The IU was far from IBM’s only contribution to the Apollo missions. The company installed an array of talent across various NASA space centers: engineers, programmers, software engineers, secretaries, accountants, clerks, administrative aides, technical writers and editors, key punch operators, stenographers, error analysts, nurses, librarians, reliability technicians, managers and assemblers. They all collaborated on a multitude of projects to guarantee NASA’s success.
At NASA’s Kennedy Space Center on Florida’s Atlantic coast, IBM engineers and technicians developed test support for the IU and produced the computer programs for the machines supporting the launch of the 3,000-ton rocket with a 40-ton payload. At NASA’s Manned Spacecraft Center in Houston (now the Johnson Space Center), they worked alongside NASA flight directors to assess the spacecraft’s trajectory from Earth’s orbit, to the lunar orbit, and back home on a minute-by-minute basis. As with Gemini, the effort was powered by the Real Time Computer Complex, comprising five System/360 Model 75 machines. They processed data from the mission on everything from the astronaut’s biomedical signs to the current temperature inside the spacecraft.
Meanwhile, at the Goddard Space Flight Center in Greenbelt, Maryland, a team of IBMers took charge of creating and monitoring a worldwide network of relay stations and ships to track and communicate with the spacecraft throughout its flight. The IBM 7094 powered the network. Dozens of them were placed at strategic points around the globe, transmitting data back to two System/360 Model 75 machines at the flight center.
The sprawling effort did not go unnoticed by NASA. “The systems information that we used to make the go, no-go decisions was developed by IBM,” recalled Eugene Kranz, one of the Apollo 11 mission’s flight directors, “and the ultimate go, no-go decision [that day] was provided to me by computers operated by IBM engineers within NASA’s Mission Control Center. Without IBM and the systems they provided, we would not have landed on the moon.”