The tri-mode seeker includes a semi-active laser, a millimeter-wave radar and an uncooled imaging infrared seeker. Some other “smart” bombs have dual-mode guidance, but Raytheon officials are not aware of a competing weapon with three guidance options. The predecessor SDB I offered only GPS guidance to fixed targets and did not contain the dual-band two-way datalink of the SDB II. The first version was also heavier, with a necessarily larger warhead that did not feature the multi-effects shaped-charge/blast-fragmentation warhead of the SDB II. The second version is also smart enough to sort, categorize and prioritize targets.
Despite the sophistication, the SDB II is “affordable,” according to Sweetman. U.S. Air Force assistant acquisition secretary Dr. William LaPlante said recently that the cost per round will be about $115,000, some $65,000 below the goal set when the SDB II entered development five years ago. Raytheon has managed its workforce well and controlled costs, he said.
The original Small Diameter Bomb, the GBU-39, in service for the last decade or so, was really rather revolutionary, among the first weapons built from the ground up to capitalize on GPS technology. It was a dandy little tool for Suppression of Enemy Air Defenses or SEAD. Against a near peer threat, SEAD will be critical to seizing and maintaining air superiority. The problem is, many modern threat air defenses are highly mobile, and the SDB I can’t attack mobile targets.
SDB II addresses this at a surprisingly low cost. That $115,000 covers the tri-mode seeker (and it will still have a GPS capability as well), the sophisticated warhead, and the airframe. Even at double the price, it would be a fairly impressive exercise in cost control.
Another benefit is that the Air Force has shown a willingness to take a system that works in one program, and leverage it across multiple programs. For instance, the Imaging Infrared Seeker used in the AGM-65D Maverick missile went on to be used in quite a few other weapon systems. Almost surely we’ll see this option used with the tri-mode seeker adapted to other weapons. An immediate though it that a kit to adapt the Mk80 series bombs much as with LGBs and JDAMs will likely follow.