How long was neil armstrong in space?

Armstrong's first mission, Gemini 8, launched in March 1966 and achieved the first docking of two spacecraft in orbit, with an uncrewed Agena target. Minutes later the joined pair began to roll. Armstrong undocked, and the rolling accelerated until the capsule was spinning fast enough to blur the crew's vision; a thruster had stuck open. He shut down the manoeuvring system and used the re-entry control thrusters to stop the tumble, after which mission rules required an immediate return. The flight ended the same day it began, in the western Pacific.

Apollo 11 lifted off on 16 July 1969 and splashed down 8 days, 3 hours and 18 minutes later. Within that span, the landing on the Sea of Tranquillity, a stay of not quite a full day on the surface and a single moonwalk shared with Buzz Aldrin account for a modest fraction of the time; the rest was the journey out and back, with Michael Collins waiting in lunar orbit aboard the command module. Quarantine came afterwards, on Earth.

That is the whole of it. Armstrong never flew again: he took a management post at NASA headquarters, resigned in 1971 and spent years teaching aerospace engineering at the University of Cincinnati, largely declining the public life that came with being first. Several of his contemporaries flew far more often, across Gemini, Apollo and later the Space Shuttle. The best-known astronaut in history made just two flights.