Milt Windler, the NASA flight director whose calm judgement helped steer the Apollo 13 crew through a lethal explosion in orbit, has died aged 94.

The mission in April 1970 is still the canonical example of competent engineering under catastrophic pressure: an oxygen tank ruptured during a routine cryogenic stirring, killing two crew and damaging the service module. What followed was improvised, and largely unplanned.

Windler managed the flight from the Mission Control room in Houston, working through options that the failure had made newly necessary while keeping a crew who could not see the damage itself working a spacecraft nobody had test-flown.

He is survived by a reputation for something rarer than heroism in a crisis — the ability to make good decisions while the information was still incomplete.