spacecraft was the second Apollo mission to orbit the Moon, and
the first to travel to the Moon with the full Apollo spacecraft,
consisting of the Command and Service Module (CSM-106, "Charlie
Brown") and the Lunar Module (LM-4, "Snoopy").
primary objectives of the mission were to demonstrate crew, space
vehicle, and mission support facilities during a manned lunar mission
and to evaluate LM performance in cislunar and lunar environment.
The mission was a full "dry run" for the Apollo 11 mission, in which
all operations except the actual lunar landing were performed.
flight carried a three man crew: Commander Thomas P. Stafford, Command
Module (CM) Pilot John W. Young, and Lunar Module (LM) Pilot Eugene
22 May Stafford and Cernan entered the LM and fired the SM reaction
control thrusters to separate the LM from the CSM. The LM was put
into an orbit to allow low altitude passes over the lunar surface,
the closest approach bringing it to within 14 km of the Moon. All
systems on the LM were tested during the separation including communications,
propulsion, attitude control, and radar. Numerous close-up photographs
of the Moon's surface, in particular the planned Apollo landing
sites, were taken. The LM descent stage was jettisoned into lunar
orbit. The LM and CSM rendezvous and redocking occurred 8 hours
after separation early on 23 May.