How long was Apollo 11 in space?

The Saturn V launched on July 16, 1969 with Neil Armstrong, Michael Collins and Edwin Aldrin aboard. After trans-lunar injection, the combined Columbia command module and Eagle lunar module took three days to arrive, entered lunar orbit, and landed on July 20, 1969 in the Sea of Tranquility. The return ended on July 24, 1969 with splashdown in the Pacific Ocean, where the aircraft carrier USS Hornet recovered the crew. In total, the mission lasted 195 hours, 18 minutes and 35 seconds.

Of that good week, only 21 hours and 36 minutes corresponded to the lunar module's stay on the surface. The single spacewalk lasted 2 hours and 31 minutes; during that time the two astronauts collected soil samples, set up a seismometer and a laser reflector, and took the photographs that define the mission's image. Michael Collins remained alone in orbit and lost radio contact with Earth every time he passed behind the Moon.

The schedule was closely dictated by the supplies and technology available. The lunar module's fuel cells, oxygen, water and batteries only lasted a few days, and the trajectory was chosen so that, in an emergency, the crew could return to Earth without complex maneuvers. Moreover, Apollo 11's main objective was to demonstrate that landing and the subsequent liftoff were possible. Only later missions, with a lunar rover and a more capable module, remained on the surface for several days, which extended the total mission duration.