GoKawiil4th March 2026
Memories, both human and magnetic
In the 1960s NASA engineers made a technical decision that would define the relationship between astronaut and spacecraft: when complex decisions, precise coordination and fast reactions were required, how should a spacecraft be controlled? They decided, in anticipation of developments in so many areas of society, that the best results would be achieved with digital execution subject to human oversight; the human brain would be paired with an artificial memory comprised of wires and magnets.
The evolution of digital computing in the middle of the 20th century placed challenging demands on memory technologies. Engineers required ever-more memory at a lower cost, faster access speed, higher density and with greater reliability than previous technologies. This provided the conditions for a creative period of iterative invention and development of magnetic memory technologies which slowed only when semiconductor-based memories came to dominate from the 1970s.
It's these magnetic memories that I decided to explore, understand (at least superficially) and illustrate. Above: A collage of my illustrations of 5 magnetic memory technologies. Click to open full-size.
Computers in spaceflight
In 1962, President John F. Kennedy famously committed NASA’s Apollo mission to landing a man on the moon before 1970. As NASA engineers scrambled to turn this objective into an achievable technical program, they came to understand the complexity of the task. Spacecraft would exceed the speed of sound, entering a new aerodynamic paradigm – and that before exiting the Earth’s atmosphere entirely and travelling by gravitational influences and thrust reaction alone. Astronauts could simply not react fast enough or in such abstract terms to control a craft travelling over 11 km/s and accurately and fuel-efficiently reach a target 384,000 km away.
Flying such a craft, they reasoned, would be more akin to extremely rapid control-feedback and solving complex equations than piloting a conventional plane. Even the lunar landing, a short period of manual control, was in fact mediated by the guidance computer, which operated feedback loops between the pilot’s controls, sensors and the craft’s actuators.
Assigning these tasks to the guidance computer led to the development of a specification; the Apollo Guidance Computer (AGC) needed to be able to make observations about the spacecraft’s state (e.g. velocity, position) at a suitable rate and then apply known information and calculations to decide which actions should be made to keep the craft on course.
Interior of Apollo spacecraft. The 'DSKY' (pronounced) or display and keyboard was the main user interface for the apollo AGC and is located above the astronaut's left hand. To execute a command the astronaut entered a 'verb' using a 2-digit code, followed by a 'noun' (also 2-digits).
... continue reading