The US Air Force plans to launch a project later this year to develop an experimental ultra-large 30,000lb (13,608kg) penetrating munition, according to service officials.
It will be optimised against hardened and deeply buried targets that existing air-delivered weapons cannot destroy, they say.
The Air Force Research Laboratory's Munitions Directorate at Eglin Air Force Base, Florida, is leading the three-phase technology demonstration, known as the Massive Ordnance Penetrator (MOP) programme. It builds on design studies that Boeing has conducted for the laboratory. Flight testing is envisaged around 2006.
Although the air force has no formal requirement for an ultra-large bomb, it has a concept for a 'Big BLU' family of massive-sized penetrator and blast munitions. The MOP demonstration will mature the technologies so that they are "on the shelf, ready to go" if a requirement emerges for a Big BLU penetrator, said Steven Butler, director of engineering at the Air Armament Center at Eglin. He told JDW that the MOP is "unlike anything" that the air force has ever built.
Interest in a big penetrating bomb is growing in some US defence circles, including the Defense Science Board (DSB), the senior policy advisory panel to the Secretary of Defense. It recommended in its February 2004 report on 'Future Strategic Strike Forces' that the Department of Defense "immediately undertake" a demonstration of a "bomber-delivered massive penetrator" weapon as part of a family of ultra-large bombs that would "improve conventional attack effectiveness against deep, expansive, underground tunnel facilities".