MIT News reported the death of Margaret Hamilton, whose work on Apollo flight software helped establish software engineering as a discipline. Her team designed defensive behavior for unexpected operator actions and prioritized mission-critical work when the onboard computer was overloaded.
That prioritization mattered during Apollo 11’s descent. The computer raised a 1202 alarm when lower-priority tasks competed for resources; the software shed those tasks and kept the landing work running. The spacecraft could continue without treating every overload as a total system failure.
The article also recalls an earlier simulator incident that led Hamilton to advocate for protections against an unsafe program being started in flight. Her proposed safeguard was initially rejected, then adopted after a similar action occurred during Apollo 8.
For present-day systems, the lesson is architectural: define critical work, establish priority and recovery behavior, and test failure paths before an emergency. Reliability comes from anticipating misuse and overload, not merely from adding capacity.







