B57 nuclear bomb

Development began at the Los Alamos National Laboratory in 1960 to meet a requirement for a multi-purpose weapon, suitable for use as a nuclear depth charge or a nuclear bomb against ground targets.

[1] Entering production in 1963 as the Mk 57, the bomb was designed to be dropped from high-speed tactical aircraft.

Some versions of the B57 were equipped with a parachute retarder (a 3.8 m/12.5 ft diameter nylon/kevlar ribbon parachute) to slow the weapon's descent, allowing the aircraft to escape the blast (or to allow the weapon to survive impact with the ground in laydown mode) at altitudes as low as 15 m (50 ft).

The B57 was produced in six versions (mods) with explosive yields ranging from 5 to 20 kilotons.

The depth bomb version of the B57, for the U.S. Navy, replaced the Mk 101 Lulu and had selectable yield up to 10 kt.