Three comprehensive official NASA documents - converted for accurate flowing-text e-book format reproduction - chronicle the incredible journey of Apollo 10, which tested the Lunar Module in lunar orbit for the first time, paving the way for the Apollo 11 landing mission. It was conducted by astronauts Stafford, Cernan, and Young in May 1969.

Two technical mission reports, the Manned Spacecraft Center (MSC) Apollo Mission Report and the NASA Headquarters Mission Operation Report (MOR), provide complete details about every aspect of the mission.

Apollo 10 MSC Mission Report: Mission description, pilots' report, communications, trajectory, command and service module performance, mission support performance, assessment of mission objectives, launch vehicle summary, anomaly summary (CSM, LM, government furnished equipment), conclusions, vehicle descriptions. Apollo 10 MOR: Mission design and execution, spacecraft performance, flight anomalies, detailed objectives and experiments, launch countdown, detailed flight mission description, back contamination program, contingency operations, configuration differences, mission support, recovery support plan, flight crew, mission management responsibility, program management, abbreviations and acronyms. Apollo 10 Press Kit: Detailed preview from countdown to landing.

The Apollo 10 mission encompassed all aspects of an actual crewed lunar landing, except the landing. It was the first flight of a complete, crewed Apollo spacecraft to operate around the moon. Objectives included a scheduled eight-hour lunar orbit of the separated lunar module, or LM, and descent to about nine miles off the moon's surface before ascending for rendezvous and docking with the command and service module, or CSM, in about a 70-mile circular lunar orbit. Pertinent data to be gathered in this landing rehearsal dealt with the lunar potential, or gravitational effect, to refine the Earth-based crewed spaceflight network tracking techniques, and to check out LM programmed trajectories and radar, and lunar flight control systems. Twelve television transmissions to Earth were planned. All mission objectives were achieved.

Apollo 10 launched from Cape Kennedy on May 18, 1969, into a nominal 115-mile circular Earth-parking orbit at an inclination of 32.5 degrees. One-and-a-half orbits later, translunar injection occurred. The S-IVB fired to increase velocity from 25,593 to 36,651 feet per second on a free-return trajectory. Twenty-five minutes later, the CSM separated for transposition and docking with the LM, similar to the maneuver performed on Apollo 9. The orbital vehicle was comprised of the S-IVB stage, and its payload of the CSM, the LM and spacecraft-lunar module adapter, or SLA, shroud. The Apollo 10 crew members were Commander Thomas Stafford, Command Module Pilot John Young and Lunar Module Pilot Eugene Cernan.