By Michael Sirak
The Air Force is launching an ambitious program to develop a sophisticated smart fuze for its bunker buster munitions, according to senior service weapons developers and recently issued documents.
The Hard Target Void Sensing Fuze (HTVSF) is a new-start program for FY ’08 that will set the Air Force anew on the path to field a long-desired fuze that can count floors and sense voids in multistory underground facilities and detonate the host munition’s warhead at the precise preprogrammed moment and spot, the senior officials said. It will leverage insights gained from the previous Hard Target Smart Fuze project that was unable to overcome technical challenges and did not result in the desired capability.
The goal of the new initiative is to field the new fuze in FY ’13 on legacy 2,000-pound and 5,000-pound penetrator munitions, Judy Stokley, deputy program executive officer for Weapons, said Oct. 10 at the 33rd Air Armament Symposium in Ft. Walton Beach, Fla. Such penetrator munitions are designed for use against hardened and deeply buried targets, such as command-and-control facilities and hidden weapons factories.
The Air Force said on Wednesday that it intends to pursue the HTVSF initially under an Office of the Secretary of Defense (OSD)-sponsored joint capabilities technology demonstration (JCTD). Two contractor teams will be selected to design, test and demonstrate their fuze concepts over a period of 27 months, according to the HTVSF presolicitation notice released Oct. 17.
The Air Force will then choose one of the teams to deliver 20 residual fuzes and proceed on to the project’s system development and demonstration phase, which will be followed by a production phase, the notice states.
The service said it anticipates selecting one of the teams for the JCTD under full and open competition and the other team under a competition restricted to U.S. sources, the notice states. But this strategy is pending the final determination of foreign-source participation, the document notes.
Bruce Simpson, director of the 308th Armament Systems Wing within the Air Armament Center at Eglin AFB, Fla., said at last week’s symposium the center is establishing an HTVSF program office. The Air Force intends to issue the request for proposals for the fuze in November and projects awarding the contracts in March 2008, he said.
The Air Force describes the HTVSF as a “cockpit programmable system that will provide multi-delay arming and detonation as well as void-sensing function…to penetrate and destroy hardened targets protected by multiple layers of reinforced material.”
The fuze will be integrated with BLU-109 and BLU-113 penetrator warheads that are used on the 2,000-pound GBU-31 Joint Direct Attack Munition and 5,000-pound GBU-28 bunker buster, respectively. The GBU-28 is carried only by the B-2A stealth bomber and F-15E multirole fighter jet, while multiple strike platforms can drop the GBU-31.
The HTVSF, in its objective form, must be able to survive and function when the host munition is penetrating 10,000 pounds-per-square-inch (PSI) to 15,000 PSI reinforced concrete, according to the fuze’s system requirements document.
Simpson said the Air Force has traditionally used 5,000 PSI reinforced concrete as the standard of measure for bunker busters. Now the standard has grown to 10,000 PSI to 15,000 PSI, he said.
“This problem has gotten even harder for us over the last few years as our adversaries have learned what our current capabilities are,” he said. “They are burying deeper and harder in their fixed sites.”
Stokley said the Air Force has overcome technical challenges standing in the way of the new fuze.
“One of the main problems, we didn’t have the data to characterize the environment, especially the lateral loads as we penetrate hard, deeply buried layered targets,” she said.
But since then, the Air Force, working with OSD and the Defense Threat Reduction Agency, has conducted tests to gather this information.
“That data is now available to all competitors,” she said. “We are really proud of that activity.”