Spacelab, a European laboratory module carried in the Space Shuttle, incorporated a French‑built Mitra 125 MS minicomputer that used 128 KB of magnetic core memory.

Spacelab was a reusable laboratory that could be configured with a pressurised habitable module or an unpressurised igloo, and it flew on multiple Shuttle missions between 1983 and 1991.

The core memory system consisted of seven printed‑circuit boards – a driver board, four core plane boards, a second driver board, and an interface board – and stored data in 294,912 tiny ferrite toroids arranged in a grid. The design employed a 2½D architecture that eliminated inhibit lines, using separate X driver circuitry for each bit and phase‑reversal techniques to halve the number of vertical drivers. Each core plane held 1024 × 288 X and Y wires, supporting 18‑bit words with parity and protect bits. The boards were densely wired with 16‑pin connectors and diode matrices to control current direction and reduce noise. Manufacturing techniques transitioned from manual wiring in the 1950s to automated production by the 1970s, allowing core memory to remain cost‑effective until semiconductor RAM became cheaper in the mid‑1970s.

Spacelab’s core memory was superseded in 1991 when the Shuttle’s main computers were upgraded to IBM AP‑101S systems using semiconductor memory, and the Mitra computers were replaced by AP‑101SL models. Core memory persists today only in the phrase “core dump”.