Introduction to Planetary Science

the urge to explore 7
Figure 1.4. Wernher von Braun (1912–1977), Director of
the NASA Marshall Space Flight Center. (Courtesy of
NASA)
the village of Peenemünde on the coast of the
Baltic Sea in northeastern Germany. Dornberger
was the military commander and von Braun
was the civilian technical director of the new
rocket-research center. One of the rockets that
was developed there was the A-4, which became
known as the V-2 when it was used by the
German Army to strike targets in Great Britain
during World War II (1939–1945). At that time,
the German rockets developed in Peenemünde
were superior to those of any other country,
although von Braun acknowledged the importance
of Robert Goddard’s work in the development
of rocket technology.
When the Russian Army approached
Peenemünde during the winter of 1944/45, von
Braun moved his entire staff and a large number
of rockets to western Germany and surrendered
to the advancing American forces. Within a few
months, he and about 100 of his engineers were
taken to Fort Bliss in Texas. From there they
traveled to White Sands, New Mexico, where
they launched V-2 rockets for high-altitude
research. In 1952, von Braun and his team
moved to Huntsville, Alabama, where von
Braun was the technical director and later chief
of the U.S. Army ballistic-weapons program.
Even though he was designing and testing
rockets for the US Army, von Braun published
several popular books between 1952 and 1956 in
which he advocated space travel and developed
plans for landing astronauts on the Moon and
Mars (See Section 1.7, Further Reading). After
the Soviet Union launched the Sputniks in
October and November of 1957, von Braun
was asked to use one of his rockets to launch
an American satellite into orbit. The launch of
Explorer 1 by a Redstone rocket took place on
January 31, 1958, and thereby initiated the exploration
of space by the USA. As a result, von
Braun who had become a naturalized citizen of
the USA in 1955, became a national hero and
leading advocate of the exploration of the solar
system.
The organization that von Braun had built up
in Huntsville was later transferred to NASA and
was renamed the C. Marshall Space Flight Center
with von Braun as its first director. The Center
developed the Saturn rockets, which were used
between 1969 and 1971 to launch spacecraft to
the Moon in response to President Kennedy’s
directive. These rockets performed flawlessly
and enabled astronauts to set foot upon the Moon.
As a result, we now have the technological
capability to explore the solar system and, in
time, to establish human settlements in space
and on other planets, as Konstantin Tsiolkovsky
envisioned more than 100 years ago.
1.3 Principles of Rocketry and Space
Navigation
Before a spacecraft built on Earth can travel
anywhere in the solar system it must have a
powerful engine that can lift it far enough above
the surface so that it can escape from the gravitational
force the Earth exerts on all objects on
its surface. The engine that is required for this
purpose must also be able to function in the upper
atmosphere of the Earth where the air gets very
“thin” and where the amount of oxygen is insufficient
to operate internal combustion engines
powered by gasoline. The only propulsion system
that can provide the necessary power and that
can operate in the vacuum of space is the rocket