📅 20 July 1969
The lunar module reached the Moon after a mission dependent on trajectory design, numerical simulation, navigation and real-time calculation.
📅 20 July 1969
Johnson calculated and checked trajectories and helped design procedures for synchronizing spacecraft in lunar orbit.
📅 20 July 1969
Mainframes, onboard guidance, ground teams and hand-prepared backup charts formed one distributed calculating system.
📅 20 July 1969
Its mathematics produced a historic achievement while relying on immense state spending, military technology and geopolitical competition.
📅 20 July 1969
Armstrong and Aldrin landed in the Sea of Tranquility while Collins remained in lunar orbit.
📅 20 July 1969
The landing prepared for direct observations and sample collection by human explorers on the Moon.
📅 20 July 1969
Michael Collins piloted the command module while the lunar module descended to the surface.
📅 20 July 1969
The landing was a milestone in human exploration of the solar system; the first steps took place later in UTC on 21 July.
