Project HARP, short for High Altitude Research Project, was a joint project of the United States Department of Defense

United States Department of Defense

The United States Department of Defense is the U.S...

 and Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

's Department of National Defence

Department of National Defence (Canada)

The Department of National Defence , frequently referred to by its acronym DND, is the department within the government of Canada with responsibility for all matters concerning the defence of Canada...

 created with the goal of studying ballistics

Ballistics

Ballistics is the science of mechanics that deals with the flight, behavior, and effects of projectiles, especially bullets, gravity bombs, rockets, or the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance.A ballistic body is a body which is...

 of re-entry vehicles at low cost; whereas most such projects used expensive (and failure-prone) rocket

Rocket

A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s, HARP used a non-rocket spacelaunch

Non-rocket spacelaunch

Non-rocket space launch is a launch into space where some or all needed speed and altitude is provided by non-rocket means, rather than simply using conventional chemical rockets from the ground. A number of alternatives to rockets have been proposed...

 method based on a very large gun

Gun

A gun is a muzzle or breech-loaded projectile-firing weapon. There are various definitions depending on the nation and branch of service. A "gun" may be distinguished from other firearms in being a crew-served weapon such as a howitzer or mortar, as opposed to a small arm like a rifle or pistol,...

 to fire the models to high altitude

Altitude

Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...

s and speed

Speed

In kinematics, the speed of an object is the magnitude of its velocity ; it is thus a scalar quantity. The average speed of an object in an interval of time is the distance traveled by the object divided by the duration of the interval; the instantaneous speed is the limit of the average speed as...

s.

Background

Started in 1961, HARP was created largely due to lobbying from Gerald Bull

Gerald Bull

Gerald Vincent Bull was a Canadian engineer who developed long-range artillery. He moved from project to project in his quest to launch economically a satellite using a huge artillery piece, to which end he designed the Project Babylon "supergun" for the Iraqi government...

, a controversial but highly successful ballistics

Ballistics

Ballistics is the science of mechanics that deals with the flight, behavior, and effects of projectiles, especially bullets, gravity bombs, rockets, or the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance.A ballistic body is a body which is...

 engineer

Engineer

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

 who went on to head the project. Bull had developed the high-speed gun technique while working on anti-ballistic missile

Anti-ballistic missile

An anti-ballistic missile is a missile designed to counter ballistic missiles .A ballistic missile is used to deliver nuclear, chemical, biological or conventional warheads in a ballistic flight trajectory. The term "anti-ballistic missile" describes any antimissile system designed to counter...

 (ABM) and intercontinental ballistic missile

Intercontinental ballistic missile

An intercontinental ballistic missile is a ballistic missile with a long range typically designed for nuclear weapons delivery...

 (ICBM) research at CARDE

Cardè

Cardè is a comune in the Province of Cuneo in the Italian region Piedmont, located about 40 km southwest of Turin and about 40 km north of Cuneo. As of 31 December 2004, it had a population of 1,077 and an area of 19.3 km²....

 in the 1950s, shooting models of high-speed interceptor missiles from guns as opposed to building supersonic wind tunnels, which would be much more expensive. The ABM project eventually ended without delivering a working system, but Bull was convinced the rocket systems he had developed had potential and started looking for other ways to use the technology.

HARP was such a development. The U.S. was in the process of testing newer ICBM systems and required repeated tests of newer re-entry vehicles. Bull suggested that the program could be run for considerably less money if the test vehicles were lofted from a large gun, as opposed to using rockets. This would also allow the test program's schedule to be greatly accelerated, as repeated firing was easy to arrange, compared to rockets. The key concept was the use of an oversized gun firing an undersized vehicle mounted in a sabot

Sabot

A sabot is a device used in a firearm or cannon to fire a projectile, such as a bullet, that is smaller than the bore diameter, or which must be held in a precise position. The term is also applied to a battery stub case, a device used similarly to make a small electrical battery usable in a...

, allowing it to be fired with relatively high acceleration. Test electronics were potted in a mix of sand and epoxy

Epoxy

Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....

, proving more than capable of withstanding the rigors of launch.

The project was based on a flight range of the Seawell Airport

Grantley Adams International Airport

Grantley Adams International Airport , is found in Seawell, Christ Church on the island of Barbados. The former name of the airport was Seawell Airport before being dedicated in honour of the first Premier of Barbados, Sir Grantley Herbert Adams in 1976. The airport's timezone is GMT –4, and is...

 in Barbados

Barbados

Barbados is an island country in the Lesser Antilles. It is in length and as much as in width, amounting to . It is situated in the western area of the North Atlantic and 100 kilometres east of the Windward Islands and the Caribbean Sea; therein, it is about east of the islands of Saint...

, from which shells

Shell (projectile)

A shell is a payload-carrying projectile, which, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot . Solid shot may contain a pyrotechnic compound if a tracer or spotting charge is used...

 were fired eastward toward the Atlantic Ocean

Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

. Using an old U.S. Navy 16 inch (406 mm) 50 caliber gun (20 m), later extended to 100 caliber (40 m), the team was able to fire a 180 kilogram slug at 3,600 meters per second (13,000 km/h 8,000 mph), reaching an altitude of 180 kilometers (591,000 ft).

The program was canceled shortly after this. The politics of the Vietnam War

Vietnam War

The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

 (then in its fifth year) and soured Canada/U.S. relations played their role in the project's cancellation. The project received just over 10 million dollars during its lifetime.

During this time, many houses and buildings within a radius of 5-10+ miles developed cracks in their concrete reinforced walls, other damage such as cracked toilets, sinks, and household infrastructure were invariably damaged when the HARP gun was fired. In fact the vibrations could easily be felt miles away and may well have felt like a minor earthquake. After the project was canceled the gun remained for years and rusted parts may still be on the site abandoned. A couple of used barrels and what appeared to be an unused barrel were also left there.
Bull's ultimate goal was to fire a payload into space from a gun, and many have suggested that the ballistics study was offered simply to gain funding. While the speed was not nearly enough to reach orbit (less than half of the 9 km/s delta-v

Delta-v

In astrodynamics a Δv or delta-v is a scalar which takes units of speed. It is a measure of the amount of "effort" that is needed to change from one trajectory to another by making an orbital maneuver....

 required to reach Low Earth Orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

), it was a major achievement at much lower cost than most ballistic missile programs.

Project Babylon

Bull never gave up on the idea of building a gun-fired satellite, but was forced to turn to other work. Through the 1970s and 80s he developed a new artillery

Artillery

Originally applied to any group of infantry primarily armed with projectile weapons, artillery has over time become limited in meaning to refer only to those engines of war that operate by projection of munitions far beyond the range of effect of personal weapons...

 piece that dramatically outperformed all others. His design, the GC 45

GC-45 howitzer

The GC-45 is a 155 mm howitzer designed by Gerald Bull's Space Research Corporation in the 1970s. Versions were produced by a number of companies during the 1980s, notably in Austria and South Africa...

, attracted wide attention. Looking for customers, Bull sold the gun to South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 (then under the Apartheid system) and then to Iraq

Iraq

Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....

. He was arrested and jailed in the U.S. for the sales to South Africa, and left Canada after his release to reside in Brussels

Brussels

Brussels , officially the Brussels Region or Brussels-Capital Region , is the capital of Belgium and the de facto capital of the European Union...

.

He then resumed work with Iraq, convincing them to build a new satellite launcher gun, Project Babylon

Project Babylon

Project Babylon was a project commissioned by the Iraqi president Saddam Hussein to build a series of superguns. The design was based on research from the 1960s Project HARP led by the Canadian artillery expert Gerald Bull...

. Saddam Hussein

Saddam Hussein

Saddam Hussein Abd al-Majid al-Tikriti was the fifth President of Iraq, serving in this capacity from 16 July 1979 until 9 April 2003...

 agreed to fund the project, but only if Bull helped with their efforts to re-design the re-entry vehicle of the SCUD

Scud

Scud is a series of tactical ballistic missiles developed by the Soviet Union during the Cold War, and exported widely to other countries. The term comes from the NATO reporting name SS-1 Scud which was attached to the missile by Western intelligence agencies...

 missiles in order to improve range. Bull agreed, making him an enemy of Iran

Iran

Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

 and Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

, the intended target of the longer-range missiles. The March 1990 assassination of Bull (allegedly at the hands of the Israeli Mossad

Mossad

The Mossad , short for HaMossad leModi'in uleTafkidim Meyuchadim , is the national intelligence agency of Israel....

 or the Iranian VEVAK intelligence agency) in his Brussels apartment, and the 1991 Gulf War

Gulf War

The Persian Gulf War , commonly referred to as simply the Gulf War, was a war waged by a U.N.-authorized coalition force from 34 nations led by the United States, against Iraq in response to Iraq's invasion and annexation of Kuwait.The war is also known under other names, such as the First Gulf...

 ended the project mid-term.

Martlet projectiles

There were several models of test projectile fired or designed during Project HARP.

Martlet 1 : The first test projectile. 16 inches (406.4 mm) gun bore, projectile weighed 450 lb (204.1 kg), was 6.6 inches (167.6 mm) in diameter and 70 inches (1,778 mm) long. Only four manufactured. Two were fired on Jan 21 and Feb 1, 1962.
Martlet 2 : Primary 16 inches (406.4 mm) test projectiles. Around 200 fired, of various weights and configurations. Most carried research payloads studying upper atmosphere and near space conditions. About half the weight of the typical Martlet 2 series projectile was in the pusher plate and centering sabot.
Martlet 2G : A more advanced projectile, which had nearly all of its total 350 lb (158.8 kg) weight in the projectile. The Martlet 2G utilized a sabot system very similar to modern antitank kinetic energy penetrator

Kinetic energy penetrator

A kinetic energy penetrator is a type of ammunition which, like a bullet, does not contain explosives and uses kinetic energy to penetrate the target....

s.
Martlet 2G-1 : A proposed space launch vehicle variant of Martlet 2G, which had a solid rocket motor in the projectile. The follow-on 2G-2 would have had a second rocket motor and been able to place the second stage in orbit, though with little or no payload.
Martlet 3 : A series of more advanced rocket propelled projectiles in the HARP project.
Martlet 3A : Intended to be a 16 inches (406.4 mm) diameter, gun fired rocket projectile able to reach 500 km altitude. The rocket motors' solid propellant deformed during firing and the design was never successful, despite several test firings.
Martlet 3B : Similar to the Martlet 3A, using steel casings and attempting to solve some of the 3A model's problems. Unsuccessful.
Martlet 3D : This model was going to be a suborbital test rocket, using the first stage of the Martlet 4 solid rocket version. As Martlet 4 was never built, no Martlet 3Ds were produced either.
Martlet 3E : A suborbital solid rocket designed to be fired from a smaller, 7 inches (177.8 mm) cannon used in the HARP project.
Martlet 4 : Two versions of full scale orbital launch vehicle projectiles were proposed in the Martlet 4 series. The first used three solid rocket motor stages and was planned to orbit about 50 pounds of payload. The second used liquid rocket motors and was planned to have orbited 200 pounds of payload. Both were about 28 feet (8.5 m) long and 16 inches (406.4 mm) in diameter, weighing about 2900 pounds (1,315.4 kg) at launch. No Martlet 4 vehicles were built; the project halted before the design was completed.

Further reading

• Gerald V. Bull, Charles H. Murphy, Paris Kanonen: The Paris Guns (Wilhelmgeschutze) and Project HARP, E. S. Mittler, Herford, 1988.

External links

• Astronautix's very detailed account of the HARP Project
• Detailed information about the Martlet projectile models at Astronautix.com
• World's Largest Gun — Popular Mechanics article by Paul Eisenstein