Bell was a pioneer in rocket-powered aircraft, having built the X-1, which was the first to break the sound barrier. In 1950 they hired Walter Dornberger, former commander of Peenemuende. He brought on board Kraft Ehricke. They sought to pick up where development at Peenemuende had left off -- to pursue development in the United States of rocket-powered, high speed aircraft for both military and civilian purposes. An attempt to recruit Eugen Saenger in France in early 1952 was unsuccessful, but the Saenger antipodal bomber became the starting point.
The first designs at Bell featured wedge wings, but as studies continued, it was obvious that the delta wing would be superior for the kind of boost-glide vehicle they had in mind. An unsolicited proposal was made to the Air Force on 17 April 1952. Bell's BOmber MIssile was a two stage vehicle very similar to NASA's fully recoverable shuttle proposals twenty years later. The first stage, with a crew of two, would accelerate the combination for two minutes, then separate and glide back to base. The second stage, with a single pilot, would press on to the target. The basic version of the vehicle, using storable liquid propellants, would reach a maximum speed of Mach 4 at 30 km altitude and glide for 6100 km. Payload would be an 1800 kg nuclear bomb. Common engines burning N2O4/UDMH propellants were proposed for both stages, the first stage having five engines, and the glider three. The booster was to be 37 m long with an 18 m wingspan, and the glider 18 m long with an 11 m wingspan. Gross lift-off mass was to be 360,000 kg,.
In May 1952 Bell received $398,459 for a one-year feasibility study of the design. This defined two variants. The suborbital version used an aluminum structure with a titanium leading edge. This would be capable of a 4800 km range and a sustained Mach 4 glide at 30 km altitude. The orbital version would be 44 m long overall, of all-titanium construction, and equipped with a graphite-epoxy spray-on ablative heat shield. Orbital capability would require the use of Lox/LH2 cryogenic propellants. The upper stage would be 23 m long, have a payload of 34,000 kg. The bomber would be capable of delivering two nuclear-weapons in a linear aft-ejecting bomb bay as was being developed for the A-5 Vigilante. The initial project paper was reviewed by the USAF in April 1953. The review found that Bell had not sufficiently resolved the problems of cooling the aircraft, and that the L/D estimates were too optimistic.
The Air Force was unimpressed with the realistic range of BOMI, but thought the concept would be useful for hypersonic research or reconnaissance. Accordingly on 1 April 1954 Bell was given a small one year $220,000 study contract to design weapons system MX-2276. This was to be a much more capable design, capable of reaching 6.7 km/sec at 80 km altitude and gliding for 22,000 km - two thirds of the way around the world.
Bell had to abandon the recoverable first stage and use staged expendable boosters to reach this speed. By the time the study was completed NACA had determined that a steady glide was preferable to Saenger's aerodynamic skipping principle on grounds of airframe heating.
The studies were extended at Bell through a number of bureaucratic twists and turns during the course of 1955. On 4 January 1955 the USAF issued Systems Requirement SR-12 for the WS-118P high-speed reconnaissance vehicle. Range was to be over 5000 km, altitude over 30 km. Bell provided a proposal on 1 December 1955, calling for a three-phase program using a glider designed to be boosted by a two-stage rocket to Mach 15 at 50 km altitude (Phase I would produce an 8,000 km range vehicle; Phase II a 16,000 km range vehicle; and Phase III an orbital vehicle).
General Operations Requirement GOR-12 of 12 May 1955 incorporated findings of the SR-12 studies and called for development of a new manned high-altitude platform by the third quarter of 1959.
In September of 1955 Bell received a funded contract extending its BOMI work under WS-118P. This was superseded in March 1956 by WS-459L, Brass Bell. Bell kept using the BOMI name in its studies through the subsequent Brass Bell and Robo studies, until they were all superseded by Dynasoar.