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