Apollo 10 Mission Log

Astronauts Gene Cernan, John Young, and Tom Stafford have personally autographed this Apollo 10 crew photo for me.
Photo Credit: NASA Image Copyright: EarthToTheMoon.com

Apollo 10 would be the second manned mission to orbit the Moon. Its primary objective was to check out the Lunar Module in lunar orbit. Apollo 10 would not attempt to land on the Moon.

The Apollo 10 crew was composed of crew of three veteran astronauts. They were Commander (CDR) Thomas Patten Stafford, Command Module Pilot (CMP) John Watts Young, and Lunar Module Pilot (LMP) Eugene Andrew Cernan.

The astronauts named the command Module Charlie Brown and named the lunar module Snoopy.

The crew chose these cartoon character names because they felt that people, especially children, could relate to those names better.

The Apollo 10 Saturn V lifted off on May 18, 1969. This was the first and only Apollo mission to lift off from launch pad 39-B at the Kennedy Space Center.

During the ascent into Earth orbit, the crew experienced a high frequency vibration in the command module. It was a tense ride. Commander Stafford stood by ready to pull the abort handle in case the vibration got any worse. After about five minutes, the vibration subsided.

The Apollo 10 crew orbited the Earth for one and a half orbits before heading off for the Moon. The crew did a maneuver known as trans lunar injection (TLI) and boosted themselves out of Earth orbit with the powerful J2 engine on the third stage.

After TLI, the Command Service Module (CSM) was separated from the third stage stack. Command Module Pilot Young then turned the CSM around to face the lunar module stored in top of the third stage. He then docked with the lunar module and extracted it from the third stage. This maneuver is known as transposition and docking.

When the crew opened up the hatches between the docked command and lunar modules they found that fiberglass insulation that protected the top hatch of the command module had torn loose. The fiberglass strands were floating everywhere and presented a breathing hazard to the crew. They attempted to clean up the fibers as best as they could but would find themselves itching from the fiberglass for the remainder of the mission.

After they were in lunar orbit Astronauts Stafford and Cernan entered the lunar module Snoopy. Astronaut Young remained in the command module Charlie Brown. The hatches were closed between the two vehicles. The vehicles undocked and the landing gear was deployed on the lunar module.

Stafford and Cernan fired the descent engine on the lunar module to lower their orbit. At one point in the orbit, lunar module Snoopy was only 8.4 nautical miles above the lunar surface. An excited Cernan radioed, "Houston, this is Snoopy! We is GO and we is down among 'em Charlie!" They were paving the way for the next Apollo mission that would attempt the first lunar landing.

The plan now was for the descent stage of the lunar module would be jettisoned and the ascent engine fired to raise the orbit for the rendezvous with the command module. As soon as the stage was jettisoned, Stafford and Cernan experienced a wild gyration in Snoopy's ascent stage.

The gyration took the crew by surprise and it took nearly 2 minutes to regain control of the vehicle. It was determined that a switch for the abort guidance system had been left in the wrong position during staging and that is what triggered the gyrations.

With the vehicle under control, the ascent stage engine brought Snoopy's orbit up for rendezvous with Charlie Brown. The two vehicles docked and Stafford and Cernan rejoined Young in the command module.

The hatches between the two vehicles were closed again and Snoopy's ascent stage was discarded into solar orbit. The crew had orbited the Moon for 31 revolutions before they headed back for Earth.

On May 26, 1969 the Charlie Brown reentered the Earth's atmosphere. The top speed that the vehicle reached at this point was 24,769 miles per hour. This was the fastest speed ever reached by human beings.

Charlie Brown splashed down in the Pacific Ocean. The aircraft carrier USS Princeton was the primary recovery vessel for this mission.

The flight duration for Apollo 10 was 8 days, 0 hours, 3 minutes, and 23 seconds.