In the mid-1950s, Bull was working on anti-ballistic missile and ICBM research at the Canadian Armaments and Research Development Establishment when he conceived a radical idea: satellites could be launched far more cheaply from an enormous gun than from a conventional rocket. By 1961 he had resigned from government work, joined McGill University as a professor, and partnered with Dean of Engineering Donald Mordell to pitch the concept. The U.S. Army's Ballistic Research Laboratory was enthusiastic - they provided two 16-inch naval gun barrels, a land mount, surplus powder charges, a heavy-duty crane, and a $750,000 radar tracking system. Project HARP was officially announced at a March 1962 press conference under McGill's Space Research Institute. For several years, the guns fired experimental shells from a test range in Barbados, reaching altitudes that grazed the edge of space.

When the Canadian government pulled HARP's funding in 1967 and the U.S. Army followed suit, Bull created the Space Research Corporation to salvage what remained. The company's main facility straddled the international border - a deliberate arrangement that would later prove useful for moving materials between countries with minimal customs scrutiny. SRC's affiliated companies stretched from Granby, Quebec to Belgium: SRCQ, Shefford Electronics Corp, SRCI, Paragon, and eventually PRB and SRCB in Europe. On this cross-border compound, Bull's team developed the ERFB shell - extended range full bore - a revolutionary design with aerodynamic fins and an elongated body that reduced drag dramatically. Combined with the GC-45 gun, it could reach ranges 30 percent farther than standard NATO artillery while maintaining superior accuracy. With Sweden's base-bleed technology added, the range extended even further.

South Africa paid for the GC-45 development. The apartheid regime needed long-range artillery, and Bull needed a customer. It has been claimed that the CIA encouraged the arrangement, viewing South Africa as a bulwark against Soviet operations in Angola. The guns became the G5 howitzer, deployed near the Angolan border in 1986 when South Africa invaded the former Portuguese colony to support UNITA against the Marxist government backed by Cuban troops and Soviet artillery. But the 1977 United Nations mandatory arms embargo prohibited exactly this kind of transaction. Bull's SRC supplied the apartheid regime with gun barrels and 30,000 shells worth over $30 million. The shipment aboard the MV Tugelaland reportedly had Israeli Military Industries' cooperation. U.S. Customs considered prosecuting 15 people but indicted only Bull and his partner Rogers Gregory.

Bull pleaded guilty in 1980, expecting a fine. Instead, he received four months in prison - a sentence that enraged him and, critically, prevented any courtroom examination of suspected U.S. government collusion in the arms exports. The conviction liquidated SRC. Bull re-incorporated the company in Brussels and continued his work for several years, reportedly pursuing his ultimate ambition: building a 'supergun' capable of launching projectiles into orbit. On March 22, 1990, Gerald Bull was shot five times outside his Brussels apartment. No one has been charged. It is widely conjectured that Mossad carried out the assassination, concerned about Bull's work with Iraq on Project Babylon - Saddam Hussein's own supergun program. After the Canadian site was abandoned, investigators found a cannon of extraordinary length, believed to have been the longest in the world.

Today the Highwater-Jay border crossing is quiet. The SRC compound that once buzzed with ballistic experiments and clandestine arms shipments has returned to the rural character of the Eastern Townships. But the story lingers in local memory and in a handful of books and documentaries - PBS Frontline profiled Bull as 'The Man Who Made the Supergun.' The landscape itself gives little away: rolling hills, mixed forest, the invisible line between nations that Bull exploited so effectively. It is a place where a single man's obsession with putting things into orbit by sheer force - not elegant rocketry but brute ballistic power - intersected with Cold War geopolitics, apartheid, and ultimately murder. The shells are gone. The guns have been removed. But the questions about who knew what, and who approved what, have never been fully answered.