The idea of guided missiles was born during World War I. The
use of the airplane as a military weapon brought about considerable thought
concerning a remotely controlled aircraft which could be used to bomb a target.
The leaders in the field were Orville Wright, who flew the first airplane; E.
A. Sperry of the Sperry Gyroscope Company; and Charles F. Kettering of General
Motors Corporation. It was these men who devised and tested our first missile,
the “Bug,” a small version of the aircraft used in those days. While the first
missile did not get into combat, a most important result of these early tests
was the recommendation that any future work should be done with
radio-controlled aircraft so that the missile could be given necessary
adjustments while in flight.
In 1924, funds were allocated for developing a missile using
radio control. Numerous, moderately successful flights were made during the
1920s with radio control. By 1932, however, the project had been listed in the
files under frills and luxuries and closed because of lack of funds.
About 1935, two brothers named Good, amateur model airplane
builders, built and flew a model plane that was remotely controlled by radio
waves transmitted from the ground. These flights were the first completely
radio-controlled flights on record.
Radio-controlled target planes were the first airborne
remote-controlled aircraft used by the U.S. Army and Navy.
By December of 1941 just before the United States’ entry
into World War II, remote-controlled aircraft were developed to the point where
they were seriously considered for use as a weapon of warfare by Gen. Arnold,
then Chief of Staff of the Army Air Corps.
So far we have discussed only the missile powered by
internal combustion engines and propellers. Work also was done to develop
missiles using the reaction-type engines, including rocket engines, which
contain within themselves all the elements needed for power, and jet engines,
which depend on the surrounding atmosphere as a source of oxygen. When a
nuclear powerplant for aircraft is developed, both the jet and rocket engines
may become obsolete insofar as missile powerplants are concerned. Let’s now
look at the progress that rocketry has made in the United States.
Development of
American Rocketry
Dr. Robert H. Goddard, at one time a physics professor at
Clark University, Worcester, Massachusetts, was largely responsible for the
sudden interest in rockets back in the 1920s. When Dr. Goddard first started
his experiments with rockets, no related technical information was available.
He started a new science, industry, and field of engineering. Through his
scientific experiments, he pointed the way to the development of rockets as we
know them today. The Smithsonian Institute agreed to finance his experiments in
1920. From these experiments he wrote a paper titled A Method of Reaching
Extreme Altitudes, in which he outlined a space rocket of the step
(multi-stage) principle, theoretically capable of reaching the moon.
Goddard discovered that with a properly shaped, smooth, tapered
nozzle he could increase the ejection velocity eight times with the same weight
of fuel. This would not only drive a rocket eight times faster, but sixty-four
times farther, according to his theory. Early in his experiments he found that
solid propellant rockets would not give him the high power or the duration of
power needed for a dependable supersonic motor capable of extreme altitudes. On
16 March 1926, after many trials, Dr. Goddard successfully fired, for the first
time in history, a liquid propellant rocket into the air. It attained an
altitude of 184 feet and a speed of 60 miles per hour. This seems small as
compared to present-day speeds and heights of missile flights, but instead of
trying to achieve speed or altitude at this time, Dr. Goddard was trying to
develop a dependable rocket motor.
Dr. Goddard later was the first to fire a rocket that
reached a speed faster than the speed of sound. He was first to develop a
gyroscopic steering apparatus for rockets. He was the first to use vanes in the
jet stream for rocket stabilization during the initial phase of a rocket
flight. And he was first to patent the idea of step rockets. After proving on
paper and in actual test that a rocket can travel in a vacuum, he developed the
mathematical theory of rocket propulsion and rocket flight, including basic
designs for long-range rockets. All of this information was available before
World War II, but evidently its immediate use did not seem applicable. Near the
end of World War II the U.S. started intense work on rocket-powered guided
missiles, using the experiments and developments of Dr. Goddard and the
American Rocket Society.
The American Rocket Society was developing rockets and
rocket motors after its organization in 1930. Its first motor was based mostly
on German designs obtained from the German Rocket Society in 1931. The American
Rocket Society was first to build a sectional rocket motor that could test
motors of different sizes and shapes, thus cutting down the cost of a new motor
for each type tested.
In 1941 some members of the American Rocket Society formed a
company known as Reaction Motors, Inc. It was organized to develop and
manufacture rocket motors for both military and civilian use.
Development of
German Rockets
The first flight of a liquid propellant rocket in Europe
occurred in Germany on 14 March 1931, five years after Dr. Goddard made his
first successful rocket test. A German scientist named Johannes Winkler was in
charge. Winkler lost his life a short time later during one of his experiments.
Germany by this time had begun to sense the future
importance of liquid propellant rockets in warfare. In 1932 Gen. Walter
Dornberger (then a captain) of the German Army obtained the necessary approval
to develop liquid propellant rockets for war purposes. By 1936, Germany decided
to make research and development of guided missiles a major project. Germany
spent $40,000,000 on a project, known as the Peenemünde Project, for
establishing a large rocket research and development laboratory. Hitler put the
members of the German Rocket Society to work there, closing to the rest of the
world German developments on rockets until after the war. Unlike Germany, the
U.S.A. during this time paid little attention to the development of jet and
rocket propulsion for any specific purpose.
Evolution of Jet
Engines
The rocket was just one type of jet propulsion powerplants
that was being proposed and worked on in this century. As early as 1913, Rene
Lorin, a French engineer, proposed and first patented the idea for a ramjet
powerplant. Lorin’s patent was followed by a Hungarian patent for a similar
device in 1928 and another French patent in 1933. None of the proposed ideas
resulted in a workable engine. The failures occurred not because the
fundamentals of operating such a device were not known but because technical
information on high-speed fluid flow was unavailable. A period of thirty-two
years separated Lorin’s original idea and the first free-flight testing of a
ramjet powered vehicle capable of developing thrust in excess of drag. This
test occurred in June 1945 when the Applied Physics Laboratory of Johns Hopkins
University successfully flew the first ramjet powered aircraft.
The forerunner of the present day turbojet was not a
thermaljet but a mechanical type. In 1927, the Italian Air Ministry began
investigating the possibility of propelling an aircraft by placing a
conventional propeller inside the mouth of a venturi-shaped fuselage. This
so-called “ducted propeller” installation was a form of mechanical jet propulsion.
Tests with this “ducted propeller” installation demonstrated that it possessed
excellent maneuverability and stability characteristics, although its overall
performance was only mediocre. In 1932, an Italian by the name of Campini
designed and later flew an aircraft propelled by a thermaljet engine. His
jet-powered aircraft was not, however, a turbojet, because it depended upon a
conventional reciprocating engine instead of a gas turbine for compressor
power.
Evaluation of Campini’s engine had hardly been made when
improved jet engines began to appear in various countries. A young British
engineer and Royal Air Force officer, Frank Whittle, had filed a patent for a
thermaljet engine as early as 1930. Whittle’s design eliminated the
reciprocating engine as the power source for driving the compressor. Instead,
the mixture of air and gases was used after combustion to drive a gas turbine.
The turbine drove the compressor. On 7 April 1941, a Gloster “Pioneer”
aircraft, powered by Whittle’s engine, became airborne during taxiing tests and
flew about 150 yards at an altitude of about six feet. On 15 May 1941, this
same aircraft made the first official takeoff for a turbojet powered aircraft
and flew for 17 minutes.
After these successful flights, the Army Air Corps sent a
special group of men to England to study the engine. Further development became
a British-American project. At this time, only ten hours of jet engine
operation had been accumulated in fifteen flights.
Turbojet development in the U.S. was turned over to the
General Electric Company because of its experience in the development and
production of turbo-superchargers. Today, turbojet engines are built and
developed by nearly all aircraft engine companies.
Another air-jet engine is the pulsejet. This type of engine
was patented by a German engineer in 1930, but a good, workable pulsejet engine
was not perfected until World War II. It became famous during the war as the
powerplant of the German “buzz bomb” or V-1. This engine was capable of propelling
the V-1 at 450 miles per hour.
In 1940, General Motors Corporation was given a contract to
build and develop jet-powered, controllable bombs which in the final version
were to be command-controlled with television. These bombs were tested
extensively in 1941 and 1942. The testing led to the development of new types
of jet-powered bombs.
Enemy Guided
Missiles of World War II
The Japanese were far behind the Germans in developing
missiles during World War II. The “Baka,” used by the Japanese during the war
was not a guided missile in the true sense of the word. It was a
rocket-propelled, piloted glide bomb designed for use against shipping targets.
The “Baka” was known as a suicide bomb. Although it achieved a certain degree
of success, it had poor maneuverability, a characteristic which resulted in
many of them being shot down by anti-aircraft fire.
The Japanese also tried an air-launched, radio-controlled,
rocket-assisted glide bomb. This missile had to be dropped from a low altitude,
and the control plane had to get within 2½ miles of the target. The procedure
made the control plane an easy target for anti-aircraft fire. The project was
dropped before the end of the war.
The German developments in the field of guided missiles
during World War II were the most advanced. Their most widely known missiles
were the V-1 and V-2 surface-to-surface missiles. As early as the spring of
1942, the original V-1 had been developed and flight tested at Peenemünde. In
1943, Germany was working on forty-eight different anti-aircraft missiles.
These were later consolidated into twelve projects for immediate development
into useful weapons. Toward the end of the war, all efforts were being directed
toward the successful production of an anti-aircraft missile capable of intercepting
Allied bombers.
The V-1 (a robot bomb) was a pilotless, pulse-jet, mid-wing
monoplane, lacking ailerons but using conventional airframe and tail
construction. All guidance and control was accomplished internally by gyro
stabilization and preset compass guidance. It was launched from a ramp 150 feet
long and 16 feet above the ground at the highest end. A speed of approximately
200 miles per hour had to be reached before the V-1 propulsion unit could
maintain the missile in flight. The missile carried a warhead weighing 1,988
pounds.
The V-1 (vengeance weapon #1) was not accurate, and it was
susceptible to destruction by anti-aircraft fire and aircraft. However, the
interruptions it caused in the functioning of a vital war center such as
London, together with the amount of physical damage it did, made the V-1
effective in lowering morale.
The V-2 (vengeance weapon #2) was the first long-range,
rocket-propelled missile to be put into combat. Concentrated efforts began in
1941. The V-2 was put into mass production, and the first V-2 landed in England
in September 1944.
The V-2 was a supersonic missile, vertically launched and
automatically tilted to a 41 to 47 degree angle a short time after launching.
The maximum range was about 200 miles, and the top speed was about 3,300 miles
per hour. The V-2 was a large missile, having a length of 46 feet 11 inches and
a diameter of 5 feet 5 inches. Its total weight at takeoff was over 14 tons,
including a 1,650-pound war-head.
Active countermeasures against the V-2 were impossible.
Except for its initial programmed turn, it operated as a free projectile at
extremely high velocity.
Five other German missiles were also highly developed during
World War II and were in various stages of test.
One of these, the “Rheinbote,” was also a surface-to-surface
missile. This rocket was a three-stage device with booster-assisted takeoff.
Its range was about 135 miles, with the third stage reaching over 3,200 miles
per hour in about 25 seconds after launching. Overall length of the rocket was
about 37 feet; but after having dropped a rearward section at the end of both
the first and second stages, it had a length of only 13 feet. The 13-foot
section of the third stage carried an 88-pound high-explosive warhead.
A surface-to-air missile, the “Wasserfall,” was a
radio-controlled supersonic rocket, similar to the V-2 in general principles of
operation. Fully loaded it had a weight of slightly less than 4 tons. Its
length was 25 feet. Designed for intercepting aircraft, this missile had specifications
which called for maximum altitude of 65,000 feet, speed of 560 miles per hour,
and range of 30 miles. Its 200-pound warhead could be detonated by radio after
the missile had been command-controlled to its target by radio signals. It also
was to use an infrared proximity fuze and homing device for control on final
approach to the target and for detonating the warhead at the most advantageous
point in the approach. Propulsion was to be obtained from a liquid propellant
powerplant, with nitrogen-pressurized tanks.
Another surface-to-air missile, the “Schmetterling”
(HS-117), was still in the development stage at the close of the war. All-metal
in construction, it was 13 feet long and had a wing span of 6½ feet. Effective
range against low-altitude targets was 10 miles. It traveled at 540 miles per
hour at altitudes up to 35,000 feet. It was to use a proximity fuze to set off
its 55-pound warhead. Propulsion was obtained from a liquid propellant rocket
motor with additional help from two booster rockets during takeoff. Launching
was to be accomplished from a platform which could be inclined and rotated
toward the target.
A third German surface-to-air missile was the “Enzian,”
designed to carry payloads of explosives up to 1,000 pounds. It was to be used
against heavy bomber formations. The “Enzian” was about 12 feet long. It had a
wing span of approximately 14 feet and weighed a little over 2 tons fully
loaded. Propelled by a liquid propellant rocket, it was assisted during takeoff
by four solid propellant rocket boosters. Launching, as in the case of the
“Schmetterling,” was from a rotatable launcher, with range elevation possible.
Its range was about 16 miles, speed 560 miles per hour, and maximum altitude
48,000 feet. Guidance was by command control. It was believed to be
gyroscopically stabilized in roll.
A German air-to-air missile, the “X-4,” was designed to be
launched from fighter aircraft as shown in the illustration. Propelled by a
liquid propellant rocket, it was stabilized by four fins placed symmetrically.
Length was about 6½ feet and span about 2½ feet. Its range was slightly over 1½
miles, and its speed was 560 miles per hour at an altitude of 21,000 feet.
Guidance was accomplished by electrical impulses transmitted through a pair of
fine wires from the fighter aircraft. The wires unrolled from two coils mounted
on the tips of two opposite fins of the missile. This missile was claimed to
have been flown, but it was never used in combat.
United States
Guided Missiles of World War II
A project for developing missiles in the U.S.A. during World
War II was instigated in 1941. In that year the Army Air Corps asked the
National Defense Research Committee to undertake a project for the development
of a vertical, controllable bomb. The committee initiated a glide-bomb program
which resulted in standardization of a preset glide bomb attached to a
2,000-pound demolition bomb. The “Azon,” a vertical bomb controlled in azimuth
only, went on the production line in 1943. Project RAZON, a bomb controlled in
both azimuth and range, was started in 1942 but not completed until the end of
the war. A medium-angle glide bomb called the “ROC” and a 12,000-pound bomb
known as the “Tarzon,” both controllable in azimuth and range, were also under
development at this time. The two bombs did not reach the combat stage during
World War II. The “Tarzon” project was dropped in 1946 and picked up again in
1948. The “Tarzon” was used successfully in the Korean action.
In 1943, a project was initiated for development of a glide
torpedo. Standard Navy torpedoes were used for this project. In the final days
of the war, these glide torpedoes were used on several missions in the Pacific
theater.
In 1944, the U.S. carried out a glide-bomb mission against
Cologne, Germany. A majority of the bombs reached the target area. In this same
year remote television-control equipment was developed and installed in bombing
aircraft. These aircraft were used to control television-sighted,
explosive-laden bombers unfit for further service. These radio-controlled
bombers saw some service over Germany under the “Weary Willie” project. Light
and radar target-seeking devices were developed for use with glide bombs and
were tested until 1945.
Our first jet-propelled missile was actually a flying-wing, jet-powered,
and radio-controlled bomb. The second version of a jet-propelled bomb was a
copy of the German V-1 with a few improvements. Another model consisted of a
combination of the two mentioned above, using the flying wing together with the
pulse-jet engine of the V-1. This project became obsolete in 1946. By 1946 the
“Tiamat,” a guided aircraft rocket, had been completed to the extent that
full-size versions were being tested.
The Navy had a number of guided missile projects under
development by the end of the war. One of these, the “Gargoyle,” was an
air-launched, powered, radio-controlled glide bomb with a flare for visual
tracking. The Navy also had a glide bomb called the “Glomb.” It was guided to a
target by radio control, monitored by television. The “Loon,” a modification of
the German V-1, was to be used from ship-to-shore and to test guided missile
components. Another missile, known as “Gorgon IIC,” used a ramjet engine with
radar tracking and radio control.
During the war, these weapons were developed under pressure
for immediate use. At the end of the war in 1945, nearly all previous
development on guided missiles, controllable bombs, and guided aircraft rockets
was considered obsolete. New military characteristics and specifications were
drawn up with future weapon possibilities in mind.
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| Japanese Ohka ("Baka"). |
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| Henschel Hs 117 Schmetterling. |
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| Ruhrstahl X-4 air-to-air missile. |
