1948 was a mere two and a half years after the end of World War II,
so military planners strategized about what a future war, if one occurred,
would look like. Two implements that had a huge effect on the previous
efforts were the atom bomb and the guided missile; therefore, they were
prominent in discussions. Germany's use of the V-1 Buzz Bomb is a familiar
example of a guided missile that struck terror in the hearts of populations
that experienced its devastating destructive power. The U.S. developed
a few missiles of its own, particularly immediately after WWII when
it had the assistance of Werner von Braun and other notable rocket scientists
who worked for the U.S. space effort after the war. A few of the missiles
are on display today at the
center of the National Air and Space Museum.
Thanks to Terry W. for providing this article.
By C.E. Chapel, 1st Lieut., U.S.M.C. (Ret.)
Consulting Ord. &
Aero. Eng. and Chief of Research & Development, Northrop Aeronautical
A new era of pilotless aircraft for war and peace
has been inaugurated. Radio and electronic equipment again plays major
role in these developments.
The "Gorgon IIC," a guided missile which can carry 1000 pounds
of general purpose explosive to the target at a speed of 100
miles per hour.
A group of guided missiles undergoing final inspection at the
Naval Air Modification Unit, Philadelphia. Each of these pilotless
aircraft is equipped with an intelligence unit enabling it to
seek out and carry its explosive load directly to the chosen
Guided missile roars into the air with the aid of four Mons-auto
rockets. After expiration of the thrust of 40,000 pounds, the
rockets and sled will fall free and the "Loon" will head out
over the Pacific to its target.
Launched by Navy "Privateer" patrol bombers outside the range
of enemy anti-aircraft fire, and guided to distant targets by
radar, these Navy "Bat" bombs sank many tons of enemy shipping.
Operating on somewhat the same principle as live bats, which
emit a short pulse of sound and direct themselves by the echoes,
robot bats are guided by radar echoes from the target. Approximately
12 ft. in length, with a 10 ft. wing span, the "Bats" carry
a heavy load of high explosives. Two "Bats" are carried by each
"Privateer," the Navy's giant patrol bomber.
Navy target drone, used for gunnery training of Navy personnel,
is prepared for a test flight by its crew.
The "Gargoyle," an air-to-ground, radio-controlled powered glide
bomb, carrying a standard 1000 lb. general-purpose or armor-piercing
payload. It can be launched from airplanes.
The "Gorgon," a guided missile resembling a freak-tailed white
shark, carries a 100-pound, specially-shaped charge and is sent
at a speed of 550 m.p.h. through air, by a rocket power plant.
The TD2N-1, an air launched target, jet powered guided missile.
The KDD "Katydid," a jet-propelled, radio-controlled pilotless
drone used as a practice target for lighter planes. The span
is 12 feet. 2.6 inches, and the length is 11.1 feet. Equipped
with a resonating jet engine equivalent to 45 hp. and having
a speed of over 200 m.p.h., it can perform all the maneuvers
of a fighter plane through radio control of the "rudder-vators"
In its V-shaped tail. It can remain aloft 40 minutes, when a
parachute packed under the forward hatch is released by a radio
signal. This turns off the jet and allows the drone to float
to earth where it can be recovered for further use.
The KAN-1 or "Little Joe." a short-range anti-aircraft missile
designed to be launched from a shipboard catapult, with the
aid of standard rockets. It is radio-controlled, flare-sighted,
and powered by "JATO." a Navy-type solid fuel rocket.
The "Gorgon" slung underneath a Navy PB4Y-2 (Navy modification
of Consolidated-Vultee's Army B-24 four-engine heavy bomber)
ready for test flight. This is an air-to-air guided unit.
The KUW-1, "Loon," pilotless aircraft propelled by jet engine.
Another type of jet powered target missile being used by the
Navy. Known as the KDD-1 "Katydid," it is designed to be launched
either by catapult or from a target-carrying aircraft.
Mockup, or exact sized model of the KAQ-1, popularly known as
the "Lark," one of the air-launched test-type guided missiles.
A radio-controlled. jet-powered target drone resting in
its launching rack under the wing of a Navy PBY. This is a small
pilotless aircraft whose flight can be made to simulate suicide
dive bombers and torpedo plane attacks. Working on the principle
that a "few hours on a drone is worth two weeks of any other
kind of gunnery training," the Navy went all out to develop
target drones for the benefit of its anti-aircraft gunners.
These target drones were frequently used while the fleet was
on its way to and returning from attacks against the enemy and
proved far more popular with the gunners than the usual type
of towed sleeve targets used by the Navy before the development
of this type of more realistic target.
The KUN-1, or "Gorgon IIC," a catapult-launched, jet-powered
guided missile, is shown mounted on a movable rack.
The "Glomb," Model LBE-1, a television-controlled glider-bomber
which can withstand a speed of 300 m.p.h. in a 4 G dive. This
is one of a atrio of pilotless craft of the same guided missile
family, the others being "Gorgon" and "Gargoyle."
The atom bomb and guided missiles will be the principal weapons for
the defense of the United States of America in any future war. None
of us want war, but we all want to be ready for it if it comes. Radio
operators, radio technicians, radio servicemen, and everyone who has
the slightest interest in the broad field of electronics should possess
a basic understanding of the fundamentals of guided missiles. Reduced
to their simplest terms, they are nothing more than new applications
of vacuum tube circuits. Definition of Guided Missile
In order to obtain a clear idea of the design, construction,
and operation of guided missiles it is necessary to agree upon certain
terms which are commonly used. First; a missile is a weapon which can
be thrown or projected through space, such as a spear, an arrow, or
a bullet. Each of these objects is guided along its flight path at the
moment of its launching, but thereafter it is subjected to various external
forces that affect the accuracy with which it travels toward the target.
Second, a guided missile may be defined as a weapon which travels
through space and carries within itself a means for controlling its
path of flight. This definition is broad enough to include bombs, rockets,
and even conventional airplanes. For example, a pilotless aircraft is
a guided missile having aerodynamic surfaces large enough to supply
the principal support for the aircraft in flight. Therefore, the lessons
learned from the operation of pilotless aircraft may be applied in the
design and construction of other forms of guided missiles.
Classification According to the Place of Launching and the Target
Guided missiles may be classified according to the
place of launching and the target. In general, they may be launched
from the surface of the earth, either from the land or from the sea,
or they may be launched from some type of aircraft. Thus, they may be
launched from the ground, from a ship, or from an airplane.
In a similar manner, guided missiles may be classified according to
their targets, which may be ground installations, ships, or aircraft.
Considering the place of launching and the target together, the classification
breaks down into the following types: (1) Ground-to-air, (2) ship-to-air,
(3) ground-to-ship, (4) ship-to-ship, (5) ground-to-ground, (6) ship-to-ground,
(7) air-to-air, (8) air-to-ground, and (9) air-to-ship.
guided missile may be used in two or more of the above classifications.
For example, an air-to-ground missile may be successfully employee as
an air-to-ship weapon. This does not necessarily mean that the same
type may be used efficiently for both military and naval purposes because
the launching conditions are often different and the tactical considerations
present entirely different problems. Thus, a guided missile which can
be launched from a heavy bombardment airplane may be too large and heavy
to launch from a comparatively small carrier-based airplane. In the
same manner, a missile which may be fired from the ground against airplanes
may be too large and heavy for a ship to launch against enemy suicide
airplanes. Furthermore, in many instances it would be a waste of valuable
armament to launch a large guided missile against a relatively small
or unimportant target when the same weapon may be needed later for an
appropriate target. Classification According to Method
A missile may be dropped from an airplane
like a rock, in which case it merely possesses the altitude and speed
given to it by the flight of the airplane, and it is brought to earth
by the force of gravity. It may be fired from a gun aboard an airplane,
it may be launched from an airplane by means of a rocket, or it may
be given an initial acceleration by means of a rocket motor and thereafter
It is obvious that any of the methods used
for launching a missile from an airplane can be used for ground launching
except a method which depends on the force of gravity. Of course, in
theory, a missile could be launched from a high tower erected on the
ground but structural limitations make this foolish, although it must
be remembered that this method was used in ancient times.
now come to a method of propulsion which is suitable for missiles launched
from either the ground or the air, and this is the use of self-propulsion,
which simply means that the missile contains a power plant of some description.
The power plant may be a reciprocating engine with a a propeller, a
gas turbine with a propeller, a turbojet motor, a ramjet motor, an aeropulse
motor, or any other kind of power plant which will drive the missile
along its path through the air.
The missile may or may not have
aerodynamic surfaces, that is, it may or may not have wings, ailerons,
a rudder, an elevator and other surfaces for controlling its flight
path. For example, glide bombs have been used, both with and without
wings and it is possible to use rockets, either with or without wings.
Pilotless aircraft using conventional types of power plants are too
slow to be effective and too large to escape enemy detection and destruction,
hence they may be eliminated from our classification of modern, practical,
guided missiles. Bullets, bombs, and artillery projectiles as we have
known them in the past should be eliminated from our thinking because
they are not adaptable to self-propulsion. In general, modern guided
missiles fall into two principal classes: (1) Rockets, either with or
without wings,: and (2) Pilotless aircraft with some form of jet propulsion.
Classification According to the Method of Control
Before we approach the control of guided missiles,
we should have a basic understanding of the control of conventional
airplanes. The aileron is a hinged, movable portion of a wing, the principal
function of which is to impress a rolling motion on the airplane. By
raising one aileron and lowering the other, the pilot can roll his airplane
to the right or left. The rudder is a movable surface hinged to the
trailing edge of the vertical stabilizer, used to steer the airplane
right or left. The elevator, usually hinged to the trailing edge of
the horizontal stabilizer, is used to raise or lower the nose of the
airplane in flight. These three types of control surfaces control the
three fundamental rotational motions of an airplane.
to relieve the pilot of work, the autopilot was developed. In its simple
form, it may be set by the pilot on a course and thereafter it operates
the ailerons, rudder, and elevator to keep the airplane on a straight
and level path. Autopilots used in World War II were either hydraulically
or electronically operated and where used in flight but were not extensively
used for take-off or landing. However, autopilots are now developed
so highly that they may be set on the ground and used from take-off
to landing without the intervention of a human pilot in the operation
of the control surfaces.
Coming back to guided missiles, in
World War II, the Germans used the types known as V-1 and V-2 with considerable
success. The V-1 was a pilotless aircraft and the V-2 was what is technically
described as an elliptical-trajectory rocket. Both of these were guided
by autopilots. The operators determined the location of the target with
regard to the place of launching, estimated the wind drift, computed
the required settings and then applied these settings before the missile
was launched. The operator had no control over the flight of the missile
after it was launched and the missile did not receive any information,
intelligence, or guidance from the target. The accuracy of its fall
upon the target depended upon the accuracy with which the autopilot
was constructed, the accuracy of its setting, and the computation of
wind drift by the operator, although the latter factor was not as important
in the case of the V-2 missile as it was in the case of the V-1. The
only electronic feature was the operation of the autopilot, assuming
that it was not of the hydraulic type.
The next step in the
development of guided missiles was to use an autopilot but control it
remotely by the exercise of the judgment of a human pilot. The human
pilot had to keep both the missile and the target under observation
constantly and exercise his remote control by means of radio. During
the night or during foggy weather, this method did not work, and even
during daylight hours, under conditions of maximum visibility, the anti-aircraft
fire of the enemy and the interception of enemy fighter airplanes reduced
Having achieved some success with radio-controlled
guided missiles under the observation of the remote pilot, the next
step was to install a television transmitter in the missile so that
it could "see" the target, that is, it would transmit its reactions
to the emission and reflection of light from the target, and thus enable
the human pilot to direct its flight by radio. Obviously, if the emission
and reflection of light from the target was weak, or if there were light
rays from objects other than the target, the accuracy was greatly lowered.
This limited the effectiveness of this method so much that the scientists
turned their attention to the use of radar.
In theory, targets
which give good radar reflections can be attacked regardless of the
visibility, thus overcoming the objection to the use of television repeat-back
information, and enabling the remote human pilot who has the necessary.
information regarding the range and direction of the target to direct
the guided missile on an accurate flight to the target. However, if
the target does not emit or reflect radar signals, this method fails.
Another theory is that if the remote human pilot knows the exact
location of the target on a map, he can track the flight of the missile
by radar, plot its course on the map, and then direct its course by
radio so that it will dive at the proper moment and hit the target.
A third theory is that a radar beam may be directed along the
path which the missile is to follow. In this case, the missile must
carry equipment which will enable it to follow the radar beam. The advantage
to this theory is that if the target, such as a ship, an airplane, or
any other movable enemy object, changes its position, the radar beam
may be directed to the new course of the target and the missile will
still strike the target. Again, a human pilot must be on watch from
the moment of launching until the fall of the missile on the target.
These theories based on the use of electronic equipment have
been seriously considered by scientists for several nations, but the
necessity for controlling the missile by the exercise of the judgment
of a human pilot has not been as attractive as the possibility of developing
a missile which would automatically seek the target.
guided missiles are sometimes called homing missiles, but this term
suggests the return of the missile to its launching point, hence it
is better to refer to them as "target seeking."
engineers play a vital part in the development of guided missiles, they
are broad enough in their thinking to consider all physical laws in
searching for new methods. For example, they have discussed the possibility
of guiding missiles to their targets by means of the emission or reflection
of sound at the target. This depends upon the intensity and direction
of the sound at the target. Battlefield noises, and even the ordinary
industrial noises, reduce the effectiveness of this method, but the
problem becomes hopeless of solution when it is realized that the missile
itself produces noise, both internally and externally, as it travels
through the air.
The emission of light from flares or searchlights,
contrasts between light and Dark areas, and similar light conditions
at the target could be used as sources of guidance for target-seeking
missiles but here again we would be faced with the obstacle of varying
conditions of visibility.
The emission of heat rays from
the smokestacks of ships, industrial plants, and similar targets, may
be used as a source of guidance, but this method is limited because
of varying weather conditions, and fluctuations in the generation of
heat at the target. Heat and light are both within the electromagnetic
spectrum, hence they emit or reflect electromagnetic radiation, but
they do not do either as well for our purposes as radar, which is reliable
night or day, regardless of weather.
In the application of radar
to the control of guided missiles, two entirely different systems have
been tried. In .
one, the missile contained only a receiver. The
transmitter was on the "mother" airplane and emitted short pulses of
high intensity. Mechanisms within the missile which kept it pointed
toward the target were activated from the returning echoes.
In the other type of radar-controlled missile, the missile is set for
a particular target, released, and then it automatically follows every
movement of the target until it strikes, leaving the mother airplane
entirely free to go on another mission.
The principle underlying
the operation of this fully automatic target-seeking missile resembles
that used by a live bat which gives out short pulses of sound and is
guided by echoes from the sound, thus avoiding collisions in the dark.
The missile emits pulsed microwave electromagnetic radiations and is
guided by the radar echoes from the target. Since the missile can follow
every movement of the target, it is possible to say that the radar robot
pilot inside the missile can "see" the target under all conditions of
A missile of this type can be carried under the
wing or fuselage of an airplane and released several miles from the
target. The usual procedure is to first locate the target by means of
the standard search radar carried by the airplane. The airplane is then
flown toward the target and the radar transmitter and receiver in the
missile are aimed in the same direction. Target information received
and transmitted from the radar in the missile is displayed on a special
indicator in the airplane and controlled by the operator. As soon as
the radar equipment can be manually adjusted to the prevailing conditions,
it is switched to automatic tracking and the missile is released.
Echoes from the target are continuously detected by the radar
receiver installed in the missile. The flight control units receive
corrective signals from the output for the purpose of guiding the missile
toward the target.
The advantages of this fully automatic, target-seeking
missile are as follows: (1) The self-guiding feature enables the launching
airplane to go on another mission and maneuver as desired: (2) The self-guiding
or homing feature increases the accuracy: (3) Heavily armed targets
outside the anti-aircraft range may be accurately attacked.
C. G. Pierce of Los Angeles, electronics engineer
for the General Electric Company. and B. L. Dorman. chief test engineer
of Aerojet, view the television installation in the test pit prior to
televising the test of firing high thrust rocket motors at Aerojet Proving
Grounds. Developed by Aerojet engineers, this method of televising rocket
motor tests was successfully demonstrated with the cooperation of engineers
of General Electric Company who furnished the television equipment.
This method, used for the first time anywhere, provides safety from
the hazard area to observers located in a remote room who may view the
tests with added advantages of better lighting and close-ups never before
The system just described was installed in
the "BAT," the first fully automatic guided missile successfully used
in combat by any nation. It was one of several guided missiles developed
by the National Bureau of Standards under the sponsorship of the Bureau
of Ordnance of the Navy Department and has led to further research on
Statements in this article are the personal
opinions of the author. They are not to be construed as necessarily
reflecting the official opinions of the Navy Department or the naval
service at large. Posted