Home history Apollo Apollo
A diverse group of 4,000 IBMers helped NASA achieve one of the greatest feats of human history — sending astronauts to the moon
The Apollo 15 roving lunar vehicle on the moon

On July 24, 1969, NASA’s Apollo 11 mission culminated with a successful splashdown into the Pacific Ocean just days after astronauts Neil Armstrong and Buzz Aldrin became the first humans to set foot on the moon. It was a safe, joyous return to Earth. The two moonwalkers, along with the mission’s command module pilot, Michael Collins, were rightfully hailed as heroes — but their historic achievement was decidedly a team effort. For years, 400,000 men and women had worked behind the scenes toward that goal. Among them: the 4,000 IBMers who built the computers, hardware and software programs to guide and track Apollo from liftoff to splashdown.

The US government first set its sights on the cosmos in the 1950s. But the Soviet Union made it there first, launching cosmonaut Yuri Gagarin into orbit aboard the Vostok 1 in 1961. With the Cold War in full effect and US national pride on the line, NASA followed a few months later by sending astronaut Alan Shepard into suborbital flight for more than 15 minutes. It prompted President John F. Kennedy, in a congressional address, to pledge to land a man on the moon before the end of the 1960s.

The space race was on.

IBM in space
A mission decades in the making

IBM had been developing the skills and tools to support a lunar mission for decades. In the 1940s, for instance, the US Navy employed an early edition of the company’s electromechanical calculator to compute the ballistic trajectories of artillery shells. In the 1950s, the US Naval Research Laboratory used the IBM 650 to perform calculations for launching the first, small satellites into space.

Meanwhile, IBM engineers created SAGE, or Semi-Automatic Ground Environment, an assemblage of early-warning radar defense systems — for which the company built its specialized AN/FSQ-7 computer, a highly durable machine boasting a yearly downtime of less than four hours. The company also developed the small, heavy-duty computers used in bombers by the US Strategic Air Command’s intercontinental ballistic missile (ICBM) Titan rockets.

And IBM played an integral role in Project Mercury and Project Gemini, NASA’s first two missions carrying astronauts. Gemini in particular was a testing ground for the moon shot — a chance to assess the craft’s durability and the astronauts’ safety during much longer flights. IBM developed and deployed advanced computer systems and programs to provide real-time tracking and health data throughout each flight.

The IU — a 2-ton ring 21 feet in diameter and 3 feet tall — was lined with mission-critical instruments
A winning machine
Designing an IU fit for a lunar mission

For the Apollo mission, NASA required a guidance system to command the Saturn rocket from liftoff into a stable orbit and onward to a lunar trajectory. Wernher von Braun, the chief architect of the Saturn V launch vehicle, and his development team enlisted IBM engineers to modify one of Gemini’s rocket computers in hopes that it would be sufficient for Apollo’s conditions. They hauled it in the back of a station wagon from an IBM campus in Owego, New York, to the Marshall Space Flight Center in Huntsville, Alabama, plugged it in, and ran it for a year without a glitch. NASA encouraged the company to make a bid for the guidance system contract.

With that, IBM engineers and technicians set to work designing the blueprint for the guiding instrument units (or IUs) that would be embedded in the Saturn rockets. The IU — a 2-ton ring 21 feet in diameter and 3 feet tall — was lined with mission-critical instruments that would monitor everything from telemetry, speed, velocity and thrust to guidance, radio communications and emergency detection systems.

That workload alone would be a challenge for any piece of machinery. But NASA also required an unprecedented degree of accuracy and efficiency. Specifically, a mean-time-between-failure of no less than 25,000 hours — a metric used to predict the length of time between a system’s inherent mistakes; and a component density — number of transistors, circuits, semiconductors — of at least 45,000 per cubic foot. IBM cleared the hurdle with ease, offering a 40,000-hour mean-time-between-failure and a component density of 250,000 per cubic foot. It secured the contract.

4,000 strong
The many responsibilities of IBMers

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.”

Without IBM and the systems they provided, we would not have landed on the moon Eugene Kranz One of the Apollo 11 mission’s flight directors
In peace for all mankind
IBM’s lasting impact on the Apollo legacy

Individual IBMers also made their own marks on Apollo. In 1966, Judith J. West was the only woman engineer working at the former Cape Kennedy (now Cape Canaveral) — and one of the few women in the program. Later, as IBM’s representative, she became the only woman on the all-male board of NASA stage contractors.

For the many exceptional men and women who ensured Apollo’s success, NASA created a recognition known as the Manned Flight Awareness (MFA) program. Many IBMers involved in the Apollo 11 mission received the MFA honor and were also included in a booklet, transferred to microfilm, that was placed on the moon during the Apollo 15 mission by astronaut James Irwin. The booklet’s cover offered a powerful message: “We came in peace for all mankind.”

As Bob Evans, president of the IBM Federal Systems Division, said at the time of the lunar landing, “Certainly Armstrong, Aldrin and Collins, as well as all of the other astronauts, must be recognized as courageous and skillful men of the highest order. But we must not forget that the men who walked on the moon were members of a far larger team. … I take enormous pride in knowing that 4,000 members of the team were IBM men and women of the Federal Systems Division.”

We must not forget that the men who walked on the moon were members of a far larger team. … I take enormous pride in knowing that 4,000 members of the team were IBM men and women of the Federal Systems Division. Bob Evans President of the IBM Federal Systems Division
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