For Future Generations: Preserving the Apollo Guidance Computer

    In my previous Spacefest article, I highlighted the experience of meeting people and interacting with historical artifacts. One of the more special of these artifacts present at Spacefest IX was space collector Jimmie Loocke’s Apollo Guidance Computer (AGC). The AGC is the computer that navigated Apollo spacecraft to and from the Moon, including the Lunar Module’s landing and ascent from the surface. Each craft in the stack, the Command Module (CM) and the Lunar Module (LM), had their own computer.

    During the Apollo program, Jimmie Loocke worked as a Thermal Vacuum Test Technician in Building 32 at NASA Manned Spacecraft Center (now Johnson Space Center). Part of the work he and his colleagues did was to human-rate the Lunar Module in the thermal vacuum chamber, simulating the environment of outer space by piping out most of the air in the chamber and fluctuating the temperature. Lunar Test Article 8 (LTA-8), one of the very first LMs intended for testing, arrived at MSC in 1967 and began undergoing these vacuum tests. Loocke recalls the LM would stay inside the chamber for more than 160 hours, and that astronauts would be inside the vehicle for some of that time. Despite his active role in the human-rating, Loocke remembers that contractors like him had very specific jobs (such as taking readings from potentiometers) and did not have an overview of the entire project. Even still, they put in lots of overtime to get the job done: “I remember one week, I worked 100 hours,” Loocke told me in our interview. The human-rating of LTA-8, as well as the vehicle’s support of missions like Apollo 11, was a landmark development in Apollo, as it essentially helped prove the vehicle’s flight-worthiness.

    Part of Jimmie Loocke’s training was to become familiar with LM systems to better understand the tests. At this point, we fast forward to 1976. Loocke was working on a new project involving speaker boxes. On a quest for electrical components, he heard about a friend's friend with a warehouse filled with hardware. Upon digging through the equipment in the warehouse, he began to recognize Apollo components. Specifically, Lunar Module components.

    It turns out the man who owned the warehouse, Virgil Redgate, had acquired the surplus hardware at NASA GSA auctions in the Houston area. Redgate had intended on extracting the precious metals and then scrapping the rest. Upon seeing the Apollo components, Loocke knew he had to save them. It turns out the boxes of equipment also included a few pieces from Mercury, Gemini, and Surveyor as well. Some hardware had documentation explaining the test history of each article, which took years for Loocke to sort through and identify exactly what he had.

    Long story short, Loocke was able to obtain over 2 tons (1800kg) of NASA hardware. The crown jewel is his Block II Lunar Module AGC, which, in synchronicity, came out of LTA-8, the same test vehicle he had worked on. Upon speaking with Jimmie at Spacefest, I soon realized the significance of his AGC doesn’t end there. The computer is in such good condition that after some maintenance, it could theoretically be turned on for the 50th anniversary of Apollo 11 next July.

    In attempting to accomplish this incredible idea, Loocke describes himself as blessed to be surrounded by experts on computer engineering. Eldon Hall, lead designer of AGC hardware and early Integrated Circuit advocate at MIT, is a friend of Loocke’s, and Hall publicly disassembled the LTA-8 AGC at the MAPLD 4 conference (Military and Aerospace Programmable Logic Devices) in 2004. Loocke recommends Hall’s book Journey to the Moon as the best AGC book available.

    One of Loocke’s contacts, Francois Rautenbach, made videos with another artifact in his possession: flown AS-202 Block I memory ropes. AS-202 was an uncrewed test of the Block I Command/Service Module flown before Apollo 1. Rautenbach’s YouTube channel shows the process of extracting those memories, and also features a video of the Block II AGC up close.

    Perhaps most importantly, Loocke knows Mike Stewart. Mike’s are the hands that are physically repairing and checking-out the AGC. He was there at Spacefest working on the project. Mike has prior experience with aerospace computers and other technological projects, but has never had a chance to work with Apollo hardware until now. Mike told me that Apollo inspired him in his youth, and that having the chance to work on the AGC with new technology has revealed things we never knew about it before. Jimmie believes that because of this project, Mike is one of the most knowledgeable people on the AGC alive.

Mike Stewart removes a logic module from the AGC at Spacefest IX.

    I asked Mike how working with 50 year old hardware/software compares to modern day stuff. He doesn’t necessarily find the AGC to be more of a challenge; but a different sort of challenge, in that the components are of a different construction. Interacting with this computer is more intricate and physically involved - touching connectors with tools and dissecting logic modules. Mike is using a modern-day program that tells him exactly where a wire flows in the AGC, which I joke with Jimmie is a program they wish they’d had in the 1960s (“You know it!” he replies). Mike and Jimmie have to find a way to recreate some components, including the connector that links the device with the spacecraft and DSKY (DiSplay&KeYboard - on the spacecraft’s control panel). If all goes well, on 20 July 2019, the AGC will run the program “Aurora-12”, the LM computer’s self-diagnostic, becoming the only operational AGC in existence.

    The July 2019 goal would be opportune, and Jimmie relates he would love the power-up to occur in the same place Apollo 11 crewmembers Buzz Aldrin and Michael Collins will be on the anniversary. Though the project is feasible, they must also acknowledge the potential risks. If the computer is not ready when it’s fired up, and, say, capacitors blow, the computer could end up in bad shape. For Jimmie, historical record and preservation is more important than blowing the works for the exact anniversary of Apollo 11.

    One thing that impresses me about Jimmie is his belief in inspiring future generations, preserving his prized possessions for history’s sake, and making sure he sells them to the right people who will look after them as he has for all these years. He describes himself not just as the components’ owner, but their “custodian” as well. He tells me, “I do believe that this is very important for future generations. We need to let future generations know where all the breakthroughs and everything came from. If you really look at things, you will see that it all seemed to start with Integrated Circuits in the AGC.”

    As is true with many NASA innovations, the AGC did more than fly Apollo to the Moon. It was one of the first times Integrated Circuits (e.g. microchips) were used practically. The Lunar Module was the first fully fly-by-wire vehicle, and its technology was adapted into aircraft soon after its development. Today, you will be hard-pressed to find new aircraft without fly-by-wire, which allows for lighter-weight components and more detailed control inputs. As stated in my prior Spacefest article, Dave Scott, now the last living person who has landed a Lunar Module on the Moon (as the commander of Apollo 15), states the AGC was the most incredible innovation out of the Apollo program. In the 1960s, most computers took up the space of an entire room. The AGC is the size of a briefcase.

The logic modules of the AGC...

...and the bare wires and circuits.

    Another challenge the project faces is financing. All this is coming out of their own pockets. As the rightful owner of the AGC, Loocke currently receives no official help from NASA, the Smithsonian, or another agency that may be interested in the project. Jimmie, Mike, and the AGC were at Spacefest thanks to crowdfunding on Facebook by event organizer Nick Howes, so that Jimmie could sell some of his collection. Each person who donated to the fundraiser received a piece of hardware, and Jimmie tells me that helping out with the AGC project could, possibly, yield a small reward as a thank you. One of his more popular sales are his small, domino-like plugs that were used in LM testing. However, he has other “big” pieces for sale as well. He owns the only known MOL (Manned-Orbiting Laboratory) computer in existence, currently for sale.

    An operational AGC would serve as a way to learn more about Apollo, just like how Mike has learned things about the AGC that are not in the discourse. Jimmie and I both believe that future generations will someday look back to Apollo, especially when humans begin revisiting the Moon, hopefully soon. More importantly, Loocke asks, “What will happen a thousand years from now?” Though it is not possible to save every piece of equipment, we must preserve something for the sake of history. Jimmie Loocke’s collection will serve as a reference for many historians to come.

    If any readers are interested in helping this project, Jimmie Loocke himself can be reached at the following email address: jimloocke1447@gmail.com

ad astra




Images and Videos Courtesy of the Author, except where noted otherwise

Cover image - Mike Stewart tests wire connections at Spacefest IX

BIBLIOGRAPHY

Ceruzzi, Paul. “Apollo Guidance Computer and the First Silicon Chips.” Smithsonian National Air and Space Museum. October 14, 2015. https://airandspace.si.edu/stories/editorial/apollo-guidance-computer-and-first-silicon-chips.

Hall, Eldon. Journey to the Moon: The History of the Apollo Guidance Computer. Reston, VA: American Institute of Aeronautics and Astronautics, 1996. http://ebookcentral.proquest.com/lib/flsouthern-ebooks/detail.action?docID=3111566.

Loocke, Jimmie. Interview with author. Telephone interview. August 8, 2018.

Scott, David. Interview with author. Spacefest IX, JW Marriott Starr Pass, Tucson, AZ. July 7, 2018.

Stewart, Mike. Interview with author. Spacefest IX, JW Marriott Starr Pass, Tucson, AZ. July 7, 2018.