Bell Rocket Belt

The Bell Rocket Belt is an early personal rocket propulsion device developed in the United States during the Cold War era. Designed to allow an individual to lift off vertically and travel short distances through controlled thrust, it represents one of the most iconic experimental jet pack systems of the twentieth century. Although never adopted for operational military use, the Bell Rocket Belt became a powerful symbol of technological optimism and has since gained lasting cultural significance through public demonstrations, films, and museums.
The device was developed by Bell Aircraft Corporation primarily for the United States Army and relied on the controlled decomposition of hydrogen peroxide to generate thrust. Despite successful demonstrations, its extremely limited flight duration and practical constraints prevented it from becoming a viable transport or combat system.

Background and Development Context

Development of the Bell Rocket Belt began in the mid-1950s at Bell Aircraft Corporation, a company already experienced in aerospace innovation. The project was initiated in response to military interest in compact personal lift devices that could enable soldiers to cross obstacles, rivers, or rough terrain quickly.
The concept was sometimes referred to internally as the “manrocket” and externally as the Small Rocket Lift Device (SRLD). At the time, the use of hydrogen peroxide as a monopropellant was already well understood in missile and torpedo technology, making it a logical choice for a lightweight propulsion system. The principal engineering challenge was not thrust generation, but achieving stable, controllable flight using the human body as the primary structural platform.

Early Research and Experimental Testing

The project was led by engineer Wendell F. Moore, who began preliminary experiments as early as 1953. Initial testing involved ground-based rigs using compressed nitrogen to simulate thrust. These rigs consisted of steel frames fitted with hinged nozzles and safety tethers to prevent excessive altitude.
Early experiments demonstrated that the human body was inherently unstable as a flight platform. Significant effort was therefore devoted to determining the correct placement of jet nozzles relative to the combined centre of gravity of the pilot and pack. These tests showed that even small changes in thrust vectoring had major effects on balance and control.
In 1959, the United States Army formally contracted Aerojet for feasibility studies and Bell Aircraft for the development of a practical flight-capable device. This funding enabled the transition from test rigs to a fully wearable rocket belt.

Design and Structural Configuration

The Bell Rocket Belt consisted of two primary structural components:

• A rigid glass-fibre corset, strapped securely to the pilot’s torso, designed to distribute weight evenly across the back.
• A rocket engine assembly, mounted on a ball-and-socket joint, allowing controlled movement in multiple directions.

Attached to the corset were three cylinders: two containing highly concentrated liquid hydrogen peroxide and one containing compressed nitrogen gas at approximately 40 atmospheres (4 MPa). The nitrogen served as a pressurising agent, forcing hydrogen peroxide into the gas generator when the pilot opened the throttle.
The rocket engine itself had no rotating or moving mechanical parts. Hydrogen peroxide passed over a catalyst bed, decomposing rapidly into superheated steam and oxygen at temperatures of around 740°C. This gas mixture was expelled through two insulated curved pipes terminating in steerable nozzles, producing thrust.

Control System and Pilot Operation

Control of the Bell Rocket Belt was achieved through two hand-operated levers extending beneath the pilot’s arms:

• The right-hand lever controlled thrust via a throttle connected to the fuel regulator valve.
• The left-hand lever controlled directional steering by adjusting the angle of the nozzle tips, enabling yaw control.

By moving the entire engine assembly using the levers, the pilot could tilt the thrust vector forwards, backwards, or sideways, allowing hovering, forward motion, and turning. Due to the extreme exhaust temperature, pilots were required to wear heavily insulated protective clothing to prevent burns.

Flight Performance and Limitations

The Bell Rocket Belt demonstrated impressive short-duration performance but severe operational limitations. Typical flight characteristics included:

• Maximum flight duration: approximately 20–21 seconds
• Maximum altitude: around 10 metres
• Maximum range: about 120 metres
• Top speed: approximately 55 km/h

During a single flight, roughly 19 litres (5 US gallons) of hydrogen peroxide were consumed. The pack, including fuel, weighed approximately 57 kilograms, making ground handling difficult and requiring a support team.
A critical safety limitation was the absence of any viable emergency landing option. The rocket belt operated at altitudes too low for parachute deployment, and engine failure would almost certainly result in serious injury. Unlike aircraft or helicopters, it offered no gliding or autorotation capability.

Flight Testing and Accidents

Testing of the wearable rocket belt began in late 1960 in a large hangar using safety tethers. Wendell Moore conducted the first series of tethered take-offs, gradually improving stability. On 17 February 1961, a tether failure caused Moore to fall approximately 25 metres, resulting in a broken kneecap and ending his role as a test pilot.
Engineer Harold Graham subsequently assumed testing duties and completed numerous tethered and untethered flights. On 20 April 1961, he performed the first free flight of the Bell Rocket Belt near Niagara Falls, flying smoothly for 13 seconds and covering a distance of roughly 35 metres. Over the following months, Graham carried out dozens of additional flights, mastering controlled turns, hovering, and circular manoeuvres.

Public Demonstrations and Military Evaluation

Between 1961 and 1962, the Bell Rocket Belt was demonstrated extensively to military officials and the general public. High-profile demonstrations included flights at Fort Eustis, Fort Bragg, and the Pentagon courtyard, as well as a private demonstration for President John F. Kennedy.
Despite widespread enthusiasm, the United States Army ultimately judged the system impractical. The extremely short flight time, minimal range, high logistical support requirements, and limited tactical usefulness led military planners to conclude that the rocket belt was more a technological curiosity than an effective combat or transport device.
By 1962, the Army cancelled further funding. Approximately $150,000 had been spent by the military, with Bell Aircraft contributing an additional $50,000 of its own resources.

Later Developments and Legacy

Although official development ceased in the 1960s, the Bell Rocket Belt concept was revived intermittently during the 1990s. Advances in materials and control systems slightly improved reliability but did not significantly extend flight duration beyond 30 seconds. The fundamental constraints of fuel density and safety remained unresolved.
Today, surviving Bell Rocket Belts are preserved as historical artefacts. One is displayed at the Smithsonian National Air and Space Museum’s Steven F. Udvar-Hazy Center, while another is held by the University at Buffalo, State University of New York.