When the USAF went shopping for a jet night-intruder and tactical bomber around 1950, the competition included home-grown designs, but the English Electric Canberra beat them in a fly-off — it climbed higher, flew farther and handled better than the American entrants. Rather than wait for a domestic aircraft, the Air Force chose to build the Canberra in the United States, a politically remarkable decision that made it the only foreign design adopted as a frontline U.S. bomber in that era.

Glenn L. Martin licence-built the type and adapted it. The most visible change was the cockpit: the British Canberra seated its crew side-by-side under a fighter-style canopy, while Martin moved to a tandem pilot-and-navigator arrangement. Less visible but more clever was the rotary bomb door — instead of conventional bomb-bay doors, the weapons were mounted on a rotating door that flipped over to expose them, cutting drag and buffet at high speed. The result was a genuinely American aircraft grown from a British seed, and it served the USAF for three decades.

As the U-2 was rushed into service, the Air Force also stretched the B-57 into a high-altitude platform. The RB-57D (first flight November 1955) roughly doubled the wing to about 106 ft using bonded honeycomb panels, trading the bomber’s toughness for the thin-air lift needed above 60,000 ft. Only about 20 were built, and the delicate wings suffered fatigue and had to be strengthened. The RB-57F (first flight June 1963) was a far more radical General Dynamics rebuild — a three-spar wing near 122 ft, TF33 turbofans and two removable J60 jet pods — that could operate above 65,000 ft. These aircraft flew sensitive reconnaissance around the edges of the Soviet bloc and China, and several were lost. Most survivors were redesignated WB-57F for weather and research work, the line NASA still flies today.

By 1970 the war over the Ho Chi Minh Trail had become a nightly hunt for trucks moving under jungle cover. The B-57G, a small batch of B-57Bs rebuilt under the “Tropic Moon III” programme, carried a nose sensor package — forward-looking infrared, low-light television and a laser designator — that let the crew detect, track and hit vehicles in darkness with laser-guided bombs. Operating from Ubon, Thailand, from October 1970, the B-57G was one of the earliest fixed-wing aircraft to combine night sensors and precision-guided weapons in combat, a direct ancestor of the way air forces attack at night today. Claims of very high per-aircraft truck tallies are widely repeated but hard to verify, and should be treated with caution.

The B-57 was a 1950s military programme built under licence, and no dependable, widely-cited flyaway unit price or cost-per-flight-hour figure survives in the open authoritative record. Any precise dollar amount attached to the type online should be read as an estimate rather than a sourced number.

The one B-57 line still flying, NASA’s WB-57 fleet, is offered to government, academic and commercial customers on a cost-reimbursable basis, but NASA does not publish a standard hourly rate. For a very-high-altitude, low-production research aircraft, real operating costs are driven by specialised maintenance and the small size of the surviving fleet — so we list the cost rows as unquantified rather than guess.