The Apollo 11 Moon Landing
Looking back in time at interesting events in history, which may or may not be related to clocks or time-keeping. Today, we look back to the the first moon walk.
July 20 was the 46th anniversary that the Apollo 11 astronauts reached the moon and Neil Armstrong stepped onto its surface. Isn’t it simply AMAZING what was accomplished! Especially considering the technology most of us now carry around in our hands every day. The technology for The Apollo Guidance Computer (AGC) had 64 kilobytes of memory (at the time, IBM described the programs it developed as the most complex software ever written). Today, your iPhone might have 32, or even 64 gigabytes of memory –the equivalent of 500,000 Apollo Guidance Computers (32 million kilobytes)! To play Pet Hotel on your iPhone you need 65 megabytes or about 1,015 Apollo Guidance Computers. The toaster in your kitchen may have a control system with more computer power and memory than the AGC that guided the astronauts to the moon.
While the astronauts would probably have preferred to fly the spacecraft manually, only the AGC could provide the accuracy in navigation and control required to send them to the Moon and return them safely home again, independent of any Earth-based navigation system. It used a real time operating system, which enabled astronauts to enter simple commands by typing in pairs of nouns and verbs, to control the spacecraft. “The Apollo program proved that computers could be entrusted with human lives. Man and machine worked in unison to achieve something that 40 years on, has yet to be surpassed,” as noted by ComputerWeekly.com’s Cliff Saran.
Over 3,500 IBM employees worked on the project. Designed by NASA, and built and programmed by IBM at the Space Systems Center in Huntsville, Alabama, the Saturn instrument unit (IU) was the computer nerve center for the launch vehicle—controlling the Saturn rocket until Apollo was safely headed to the Moon. It determined when to fire the Saturn’s three rockets, when to jettison them and where to point them. Included in the IU’s equipment complex were devices to sense altitude, acceleration, velocity and position, as well as the computer to lay out the desired course and give control signals to the engines to steer the Saturn on that course.
“I remember thinking, Oh my God, it worked,” the pioneering software engineer Margaret Hamilton told TIME Magazine. “I was so happy. But I was more happy about it working than about the fact that we landed.”