How NASA Built Artemis II's Fault-Tolerant Computer

Logan Kugler details the Orion capsule's flight computer architecture on the Artemis II mission, which moves well past the Apollo Guidance Computer and the conventional triple-modular-redundancy playbook. Orion runs eight CPUs in parallel across four Flight Control Modules (each a self-checking pair) on a time-triggered Ethernet network, choosing a "fail-silent" design over majority voting: a faulty module shuts up rather than emit a wrong answer, and the system selects from the next healthy module in priority order. A fully dissimilar Backup Flight Software system on different hardware and OS guards against common-mode software failure. Carnegie Mellon SEI's Michael Riley notes that this kind of architectural discipline is increasingly rare — modern Agile/DevOps cycles favor iteration, which can erode the determinism that mission-critical software requires. A useful reference for thinking about reliability engineering, dissimilar redundancy, and where time-partitioned schedulers buy you something the consumer-software stack can't.