Apollo 10

Apollo 10 rehearsed a lunar landing mission without touching the surface. Thomas Stafford, John Young, and Eugene Cernan launched on May 18, 1969, taking the complete command-and-service-module and lunar-module combination to the Moon for the first time. Young remained aboard Charlie Brown while Stafford and Cernan flew Snoopy independently in lunar orbit. The lunar module descended to roughly 15 kilometers above the surface, testing landing radar, guidance, communications, and the approach to the planned Apollo 11 landing region. The crew then separated its stages and performed the ascent-stage rendezvous and docking sequence. A brief unplanned rotation during staging was controlled, adding practical experience with the spacecraft's control systems and procedures. After rejoining Young, the crew completed photography and tracking work before returning to Earth. Apollo 10 splashed down in the Pacific on May 26, demonstrating nearly the entire flight sequence required for the first lunar landing.