The Apollo 10 mission was a complete staging of the Apollo 11 mission without actually landing on the Moon. The mission was the second to orbit the Moon and the first to travel to the Moon with the entire Apollo spacecraft configuration. Astronauts Thomas Stafford and Eugene Cernan decended inside the Lunar Module to within 14 kilometers of the lunar surface achieving the closest approach to the Moon before Apollo 11 landed two months later.
The Apollo 10 spacecraft was launched from Cape Kennedy at 12:49 p.m., EDT, on May 18, 1969. This liftoff marked the fourth manned Apollo launch in the short space of seven months. After the spacecraft completed one and a half revolutions of the Earth, the S-IVB booster stage was reignited to increase the speed of the spacecraft to the velocity required to escape the gravitational attraction of the Earth. Three days later, the spacecraft was placed in a 60- by 170-nautical miles orbit around the Moon. After the spacecraft completed two revolutions of the Moon, orbit was circularized to 60 nautical miles by a second burn of the service propulsion system.
Nineteen color television transmissions (totaling 5 hours 52 minutes) of remarkable quality provided the world audience the best exposure yet to spacecraft activities and spectacular views of the earth and the moon.
On the fifth day of the mission, Astronauts Thomas P. Stafford and Eugene A. Cernan descended in the lunar module to an altitude of less than 47,000 feet (14,326 meters) above the Moon. At this altitude, two passes were made over the future Apollo 11 landing site. The LM then completed a successful rendezvous with Astronaut John W. Young in the command module.
During the mission, the astronauts obtained hundreds of still photographs and exposed many reels of motion-picture film.
On May 24, the service propulsion system was reignited, and the astronauts began the return journey to Earth. Splashdown occurred at 12:52 p.m. on May 26, 1969, less than 4 miles (6.4 km) from the target point and the recovery ship.
From NASA SP-232, Analysis of Apollo 10 photography and visual observations.