Space Gun: A Bold Idea with No Prospects
Launch of the "projectile wagon" from the giant Columbiad cannon. Illustration by Henri de Montaud for Jules Verne's "From the Earth to the Moon in 97 Hours and 20 Minutes"
At present, the entire space industry is based on missile technology, which has a number of important advantages and benefits. However, in the past, alternative methods of launching payloads into low-Earth orbit have been proposed. For example, there was the concept of a special artillery High-energy systems that could launch spacecraft are being considered. However, none of these ideas have reached full implementation.
Theory and Literature
Interestingly, the concept of launching orbital objects by artillery appeared long before the idea of using rockets for this purpose—as early as the late 17th century. Isaac Newton, in his work "Philosophiæ Naturalis Principia Mathematica," proposed an interesting thought experiment in the field of propulsion and ballistics. Of course, the practical application of such ideas was not envisaged.
Newton imagined a hypothetical mountain rising above the Earth's atmosphere and "placed" a cannon with a zero-angle elevation on its summit. Calculations showed that increasing the propellant charge would increase the projectile's range. Moreover, a high-power charge could impart high velocity to the projectile and send it into orbit.
In 1865, the distinguished writer Jules Verne published his novel "From the Earth to the Moon in 97 Hours and 20 Minutes." The novel's protagonists, a group of American enthusiasts, built a unique, super-large-caliber cannon capable of launching a special "projectile wagon" on a trajectory to the moon. As in his other books, Verne generously described the technology and techniques involved.
A real "space gun." One of the weapons used in the HARP program. Photo: Geraldbullexpocanon.blogspot.com
Subsequently, the idea of a "space gun" providing access to orbit or celestial bodies repeatedly appeared in various works of fiction. Science fiction writers, filmmakers, video game creators, and others have addressed the topic.
First steps
At the end of the 19th century, K.E. Tsiolkovsky, I.V. Meshchersky, and many other scientists collaborated to develop a theory of rocket propulsion. The potential of rocket systems was demonstrated, including in the context of space exploration. The subsequent development of rocket and space technology was based precisely on these principles. The idea of artillery launching, however, was virtually forgotten.
Nevertheless, calculations and research into high-power guns with special characteristics continued. It was discovered that a projectile's flight along a high ballistic trajectory allows for increased firing range. This is because part of the projectile's path in this case lies in a thin atmosphere, reducing air resistance and the energy required to overcome it.
Similar ideas were used in several ultra-long-range weapon projects. For example, in 1944, Nazi Germany briefly used the V-3 cannon. This multi-chamber system with a barrel approximately 130 meters long fired special extended projectiles to a range of 160-165 km. In flight, these projectiles rose to an altitude of approximately 40 km.
Practical implementation
In the late 1940s, leading countries accelerated their work on missile weapons. To test new technologies, they needed specialized wind tunnels, test rigs, and test ranges with the appropriate equipment. In Canada, a team of specialists led by the young scientist Gerald Bull was preparing such a range. Instead of a wind tunnel, they decided to use a modified 140mm field gun. This gun would launch model rockets at the required speed. In the 1950s, Bull prepared a similar range in the United States.
J. Bull (right) and Donald Mordell of McGill University demonstrate the Martlet-1 projectile. Photo: GettyImages
In late 1957, amid the hype surrounding the launch of the first artificial satellite, J. Bull made a bold announcement. He told the press that existing technology made it possible to create a weapon for sending payloads into low-Earth orbit. However, the sensation was unfounded—no one at the time was planning to build a "space gun."
In 1961, J. Bull transferred to McGill University in Montreal. Together with university staff, he developed a plan for the High Altitude Research Project (HARP). They soon secured financial support from the Canadian and US military departments.
The HARP project envisioned the use of a large-caliber cannon mounted on a special mount capable of firing at high elevation angles or vertically upward. Special projectiles optimized for high-altitude launches were also developed, collectively known as Martlet.
A HARP test site was established on the island of Barbados. Two additional sites were later established in the United States. Special installations for the experimental weapon and other facilities were built at three test sites. The experimental "space gun" was based on the barrel of a 16-inch (406,4 mm) naval gun. It used the Martlet-1 projectile, designed as a stabilized rocket.
The first HARP launch took place on January 20, 1963. A simplified projectile, designed to test the launch's feasibility, ascended to only 3 km. The following day, a full-scale Martlet-1 munition was used, reaching an altitude of 26 km. Several subsequent launches followed, with similar results.
One of the HARP missiles fired. Photo: US Department of Defense
In April, testing of the improved Martlet-2 projectile began. This missile was successfully launched 92 kilometers. It could carry a payload of several kilograms, depending on the required trajectory and flight altitude.
In September, the Martlet-3A was submitted for testing. This was a fully functional rocket with its own solid-fuel motor. Jet propulsion could significantly improve the rocket's flight characteristics and/or payload capacity. In 1964-65, the three-stage Martlet-4 rocket was developed, which could carry a payload of up to 50 pounds (22,7 kg) and launch it into low orbit.
HARP testing continued until early 1967. Canada and the United States then lost interest in the unusual project and ceased funding. The tests achieved a maximum altitude of 180 km and theoretically demonstrated the feasibility of launching payloads into orbit.
J. Bull later founded his own company, Space Research Corporation, and continued to develop HARP ideas. However, the "space gun" idea gradually faded into the background, with military projects taking priority. SRC collaborated with Israel, South Africa, and China, which led to a number of problems.
In the early 1980s, J. Bull, commissioned by Iraq, began developing the Babylon ultra-long-range weapon. In 1989, the project reached field testing. However, in March 1990, J. Bull was assassinated by unknown assailants. Furthermore, third-party intelligence agencies were able to prevent the delivery of Babylon components to Iraq. The project was abandoned.
A Martlet-2G projectile for the HARP cannon. Photo: Geraldbullexpocanon.blogspot.com
New attempt
In the 1980s, the Lawrence Livermore National Laboratory of the US Department of Energy attempted to reimagine the HARP project. As part of the Super HARP program, they developed a long-barreled gun using a methane-based gas mixture instead of gunpowder. It also featured a pneumatic system for storing and transmitting momentum using compressed hydrogen. However, the entire gun design had to be developed from scratch.
The first firings took place in 1992. During testing, a muzzle velocity of approximately 3 km/s was achieved. Plans were underway to further enhance the performance and achieve a velocity of 7 km/s, sufficient for launching a payload into low Earth orbit.
However, work soon halted due to a lack of clear progress, questionable prospects, and excessive costs. The SHARP project was abandoned, although it was subsequently repeatedly mentioned as a source of various technologies. Furthermore, the experimental weapon was used as a launcher for aerodynamic models of advanced technology.
Objective problems
In recent decades, various organizations and enthusiasts have regularly revived the concept of a specialized cannon for orbital launches. However, it never progressed beyond preliminary studies and publicity. The unusual idea never gained traction, and space exploration remains reliant on rocket technology.
An abandoned HARP weapon at a firing range in Barbados. Photo: Wikimedia Commons
It's easy to see that the "space gun" has a number of inherent problems, which become apparent even at the basic concept level. Additional difficulties and challenges arise when attempting to implement this concept as a design or a fully-fledged system "in metal."
The main challenges of "space guns" lie in the areas of speed and energy. It's worth remembering that to reach Earth orbit, an object must reach the so-called first cosmic velocity—approximately 7,9 km/s. Barrel systems based on existing propellants and alternative solutions cannot accelerate a projectile to this speed.
To increase muzzle velocity and energy, it is necessary to increase the pressure in the barrel. This increases the strength requirements for the barrel, bolt, recoil mechanisms, etc. A weapon with increased strength would be too heavy and difficult to manufacture and operate.
The HARP program used off-the-shelf barrels of up to 406 mm caliber, borrowed from naval mounts. The Martlet series projectiles were developed from scratch. They were fin-stabilized and effectively sub-caliber. This design negatively impacted the internal volume available for cargo. Furthermore, even the latest versions of the Swift carried less than 30 kg of cargo.
Increasing the caliber, which will allow for the use of a larger projectile, further complicates the gun's design and installation. Furthermore, the requirements for its energy characteristics increase. This necessitates a more robust design, which will be complex, heavy, and expensive.
Gun barrel and carriage components. Photo: Wikimedia Commons
J. Bull and his colleagues attempted to address some of the "space gun's" shortcomings. For example, to improve energy and speed, they decided to use rockets, including multistage ones. This approach allowed them to reach an altitude of 180 km, but did not solve other problems. The launch system remained overly complex, and the rocket's payload remained limited.
Meanwhile, the Lawrence Livermore Laboratory used a fundamentally new methane-based propellant charge and a hydrogen-fueled energy transfer system. These achieved a significant performance boost compared to artillery propellants. However, the energy level achieved remained insufficient.
It's worth noting that the HARP project achieved some interesting technical results. For example, early versions of the Strizh rocket without an engine cost no more than $3-$4. Rockets of this family were significantly more expensive. Nevertheless, the unit cost of launching a kilogram of payload into orbit remained relatively low even by today's standards.
No prospects
Thus, the artillery method of delivering payloads into orbit appears, at first glance, interesting and promising. However, it suffers from a number of inherent problems and shortcomings that have yet to be overcome. The few attempts to create real "space guns" have predictably ended in failure.
At the same time, launch vehicles of various types have demonstrated their potential and firmly established themselves in the space sector. Development in this area continues and is yielding the desired results. However, rockets have become unrivaled in comparison with alternative solutions, including specialized artillery, and this situation is unlikely to ever change.
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