By the early 1960s, the race to space was dominated by rockets. Yet one engineer believed there was a cheaper and potentially more efficient alternative. That engineer was Gerald Vincent Bull, a Canadian ballistic expert whose ambitious Project HARP sought to launch scientific payloads into the upper atmosphere using a giant cannon rather than conventional rockets.
Although the project ultimately failed to revolutionize spaceflight, it produced remarkable technical achievements and remains one of the most unconventional aerospace programs ever attempted. Bull’s later association with Saddam Hussein’s Iraq and his unsolved assassination would make his life story even more extraordinary and controversial.
The Making of a Ballistics Pioneer
Born in Ontario, Canada, in 1928, Gerald Bull showed an early aptitude for engineering and physics. After studying at the University of Toronto, he became involved in military and aerospace research, specializing in ballistics, aerodynamics, and artillery systems.
Bull was convinced that large-caliber guns could play a role far beyond warfare. He believed a sufficiently powerful cannon could launch scientific instruments, and eventually satellites, into space at a fraction of the cost of rockets. During an era when space launches were extraordinarily expensive, the idea attracted serious attention from both Canadian and American defense researchers.
Project HARP: A Radical Alternative to Rockets
In 1961, Bull became the driving force behind the High-Altitude Research Project, better known as Project HARP. The joint U.S.-Canadian initiative was supported by the U.S. Department of Defense, Canada’s Department of National Defence, and researchers at McGill University.
The project’s goal was to study the upper atmosphere by firing instrumented projectiles to extreme altitudes. Rather than relying on rocket propulsion, HARP employed modified 16-inch naval guns originally designed for U.S. battleships.
The concept was straightforward in theory. A massive gun would accelerate a specially designed projectile to extraordinary speeds, allowing it to travel into the upper atmosphere. The payload would carry scientific instruments capable of gathering information about atmospheric conditions, high-altitude flight, and reentry dynamics.
For Bull, HARP was more than a research project. It was a proof of concept for a future in which satellites could be launched by artillery, dramatically reducing the cost of access to space.
Bull believed that a giant gun could do for spaceflight what mass production had done for aviation: dramatically lower the cost of reaching the sky.”
Record-Breaking Launches
One of the project’s principal testing sites was located in Barbados, where a pair of modified naval guns were mounted to fire nearly vertically. Additional testing occurred at Yuma Proving Ground in Arizona.
The project developed a series of specialized projectiles known as Martlet vehicles. These slender, high-velocity rounds were engineered to survive the enormous forces generated during launch while carrying scientific instruments.
Project HARP achieved several significant successes. Its most famous accomplishment came when a gun-launched projectile reached an altitude of approximately 180 kilometers (112 miles), setting a record for the highest altitude ever attained by a projectile fired from a gun.
The program demonstrated that artillery could perform valuable scientific missions at comparatively low cost. Researchers gathered atmospheric data from altitudes difficult to reach using aircraft or weather balloons, and the project proved that extremely large guns could function as viable high-altitude research platforms.
Why HARP Failed
Despite its successes, HARP faced major limitations.
The acceleration forces generated by the giant guns were immense, severely restricting the kinds of payloads that could survive launch. Sensitive electronics, delicate instruments, and any future human passengers would face extraordinary engineering challenges.
At the same time, conventional rocket technology was advancing rapidly. Rockets became more reliable, more capable, and increasingly practical for launching spacecraft and satellites.
As government priorities shifted, funding for HARP dwindled. By the late 1960s, the program was cancelled before Bull could pursue his ultimate goal of placing satellites into orbit using artillery. For many engineers, Project HARP was an intriguing dead end. For Bull, however, it remained an obsession.
From Space Dreams to Superguns
Following HARP’s cancellation, Bull continued pursuing advanced artillery concepts. He founded Space Research Corporation and became internationally recognized for designing long-range, high-performance artillery systems.
His work eventually attracted both customers and controversy. During the 1980s, Bull became involved with Iraq under the rule of Saddam Hussein. The Iraqi government sought his expertise for an ambitious weapons and aerospace initiative known as Project Babylon.
Project Babylon proposed the construction of an enormous supergun far larger than any artillery piece previously built. The design echoed many concepts Bull had explored during Project HARP. Bull maintained that such a weapon could be adapted for peaceful purposes, including launching satellites and scientific payloads into space.
Many Western governments and intelligence agencies viewed the project differently. Critics feared that the technology could provide Iraq with new strategic military capabilities or support weapons development programs. As a result, Project Babylon became one of the most closely scrutinized engineering programs of its era.
Assassination and Mystery
On March 22, 1990, Gerald Bull was shot dead outside his apartment in Brussels, Belgium. He was 62 years old and deeply involved in what had become the most controversial project of his career: Iraq’s Project Babylon.
The murder immediately attracted international attention. Bull was found in the hallway outside his apartment, having been struck by multiple gunshots in what investigators believed was a carefully planned execution. There were no signs of robbery, and personal possessions remained untouched. To many observers, the killing bore the hallmarks of a professional intelligence operation.
Belgian authorities launched an investigation, but despite extensive inquiries, no one was ever arrested or charged. More than three decades later, the assassination remains officially unsolved.
Bull’s death came at a time when Western governments were increasingly alarmed by his work for Iraqi leader Saddam Hussein. Since the late 1980s, Bull had been assisting Iraq in the development of Project Babylon, an ambitious supergun program that drew upon many of the concepts he had pioneered during Project HARP. While Bull continued to describe the technology as having potential civilian applications, including the low-cost launch of satellites, intelligence agencies viewed the project through a far more strategic lens.
The prospect of Iraq acquiring an enormous long-range artillery system generated concern throughout the intelligence community. Some analysts feared the technology could be adapted for military purposes or used in conjunction with Iraq’s wider weapons programs. As scrutiny intensified, so did speculation about who might have wanted Bull eliminated.
Over the years, numerous theories have emerged. The most persistent has focused on Israel’s intelligence service, Mossad, which had closely monitored Iraq’s military development programs throughout the 1980s. Israel had previously demonstrated its willingness to take direct action against perceived strategic threats, most notably in the 1981 destruction of Iraq’s Osirak nuclear reactor. As a result, many journalists, intelligence writers, and historians have suggested Mossad as the most likely suspect.
Yet no government has ever acknowledged responsibility, and no conclusive evidence has been made public. Other theories have pointed to Iranian intelligence, Western intelligence services, rival arms interests, or even elements within Iraq itself. None of these possibilities has been definitively proven, leaving Bull’s death one of the enduring mysteries of late Cold War espionage.
No one has ever been charged with Gerald Bull’s murder, and the identity of his killer remains one of the intelligence world’s most enduring mysteries.”
Whatever the identity of his killer, Bull’s assassination dealt a severe blow to Project Babylon. As international attention focused on Iraq’s procurement network, customs officials and investigators across Europe began intercepting major components intended for the massive supergun. Large steel sections manufactured by European firms were seized before they could be assembled in Iraq, exposing the true scale of the project.
The final chapter came only months later. Following Iraq’s invasion of Kuwait in August 1990 and the subsequent Gulf War, Project Babylon effectively collapsed. Remaining components were confiscated, dismantled, or destroyed, and the giant gun that Bull had envisioned never became operational.
In death, as in life, Gerald Bull remained an enigmatic figure. To some, he was a brilliant engineer whose unconventional ideas challenged the economics of spaceflight. To others, he was a gifted technologist whose ambitions led him into dangerous geopolitical territory. His murder, like many aspects of his career, remains shrouded in uncertainty, ensuring that the story of Gerald Bull continues to fascinate historians, intelligence researchers, and aerospace enthusiasts alike.
A Complex Legacy
Today, Gerald Bull remains one of the most fascinating and polarizing figures in aerospace and military engineering.
Supporters view him as a visionary innovator whose ideas challenged traditional assumptions about how humanity might reach space. Project HARP demonstrated that artillery technology could achieve altitudes once thought possible only with rockets, and many of Bull’s technical innovations influenced later developments in high-velocity projectile design.
Critics argue that his willingness to work with controversial governments, particularly the regime of Saddam Hussein, undermined his scientific legacy and placed his expertise at the service of dangerous political ambitions.
More than three decades after his death, Bull’s story continues to captivate historians, engineers, and space enthusiasts. His dream of using giant guns to reduce the cost of space access never became reality, but Project HARP remains one of the boldest and most imaginative experiments of the Space Age, and its creator remains one of the era’s most enigmatic figures.