Apollo 10 was a NASA mission launched on May 18, 1969, as part of the Apollo program. It served as a "dress rehearsal" for the first moon landing, testing all the components and procedures needed for Apollo 11. The mission included a complete orbit around the Moon and a descent to within 8.5 nautical miles of the lunar surface. The crew consisted of Thomas Stafford, John Young, and Eugene Cernan. They successfully completed their mission, demonstrating the capabilities required for a lunar landing. Apollo 10 remains significant in space exploration history for its contributions to the success of subsequent missions.