The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

An American-manned space program that built on
the achievements of Mercury and Gemini and
eventually landed 12 astronauts on the Moon. Undertaken
at a time of intense military rivalry with the
Soviet Union, it demanded rapid progress in all
aspects of spaceflight. Apollo hardware was also used
for other missions, including Skylab and the Apollo-
Soyuz Test Project.
Apollo history
On July 29, 1960, NASA unveiled a plan to develop
a three-man spacecraft, called Apollo, capable of
operating in low Earth or circumlunar orbit. President
Eisenhower initially opposed this development
beyond the Mercury Project, but Apollo was given
the green light by his successor on May 21, 1961,
when President Kennedy declared America’s goal of
placing humans on the Moon by the end of the
decade. As a NASA historian observed, 141 the decision
“owed nothing to any scientific interest in the
Moon. The primary dividend was to be national prestige.”
Not surprisingly, given that beating the Soviets
was the main objective, public and government interest
in Apollo rapidly waned after the Space Race was
won.
NASA leaders had to choose between three ways of
getting astronauts to and from the lunar surface: direct
ascent, Earth orbit rendezvous, and lunar orbit rendezvous.
Direct ascent meant sending a single spacecraft
on a straight shot from Earth’s surface to the
Moon’s surface with enough propellant for the return
journey, and could only be done with the development
of a huge new rocket known as the Nova. Earth
orbit rendezvous involved first placing the moonship
in low Earth orbit, then fueling its booster—a scheme
that called for the launch of two Saturn Vs. Only the
lunar orbit rendezvous approach would enable the
mission to be accomplished with the launch of a single
Saturn V, and mainly for this reason it was the one
selected by NASA in June 1962.
North American Aviation was chosen to develop
the main part of the craft, the so-called Command
and Service Module, which could operate together
with or independently of a special Lunar Module. To
speed development, Apollo vehicles were built in
Apollo
two configurations: Block 1 and Block 2. The former
was intended only for test missions in Earth orbit;
the latter was more sophisticated and reserved for
the Moon shots themselves. However, following a
fire, which cost the lives of three astronauts (see below),
the Apollo design was overhauled and no
Block 1s were launched with a crew aboard. The rest
of the Apollo program proved to be a triumph of
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technology and human endeavor.
Apollo spacecraft
Carried into space atop a Saturn launch vehicle were
the Command Module (CM), the Service Module
(SM), and the Lunar Module (LM). Unmanned test
flights and one manned test flight, Apollo 7, were
launched by Saturn IBs; all other manned Apollos
were launched by Saturn Vs.
Command Module (CM)
A conical three-man capsule that served as the control
center and main living area; the CM was the
only part of Apollo built to withstand the heat of
reentry. The forward section contained a pair of
thrusters for attitude control during reentry, parachutes
for landing, and a tunnel for entering the LM.
At the end of the tunnel was an airtight hatch and a
removable docking probe used for linking the CM
and the LM.
Crewmen spent much of the time on their couches
but could leave them and move around. With the
seat portion of the center couch folded, two astronauts
could stand at the same time. The astronauts
took turns sleeping in two sleeping bags mounted
behind the left and right couches. Food, water, clothing,
waste management, and other equipment were
packed into bays that lined the walls of the craft. The
pressurization (about one third of sea-level pressure),
temperature (about 24°C), and controlled atmosphere
afforded a shirtsleeve environment. Spacesuits
were worn only during critical phases of a mission,
such as launch, reentry, docking, and crew transfer.
The left-hand couch was occupied by the commander,
who in addition to assuming the duties of
command normally worked the spacecraft’s flight
controls. The center couch was for the CM pilot,
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