Cores in space: The core memory module from a 1980 Spacelab computer

Spacelab was a reusable laboratory that could be carried in the Space Shuttle's cargo bay, providing lab space for astronauts and experiments.1 Because Spacelab was a European project, it used a French-built minicomputer, the Mitra 125 MS,2 rather than the Shuttle's main computers, IBM-built AP-101 systems. For storage, the Spacelab computer contained 128 kilobytes of RAM. Rather than silicon memory, the computer used magnetic core memory, with each bit stored in a tiny ferrite ring. In this article, I take a close look at this computer's core memory system. The core stack from the Spacelab computer. I removed the top board to show the core planes. The illustration below shows how Spacelab fit inside the Shuttle's cargo bay. The pressurized laboratory is the cylindrical module in the front of the cargo bay, connected to the Shuttle by a tunnel. Experiments were mounted on pallets behind the laboratory. The laboratory held three identical Mitra computers.3 One computer managed Spacelab…