Previous trials conducted at Sweden’s Vidsel Test Range in February 2015 proved that Boeing's GBU-39B SDB I bomb, which was originally designed for launching from an aircraft, could be launched from the ground and guided to its target by the same GPS-aided inertial navigation system. The testing showed that the bomb can withstand a rocket artillery launch without its performance being compromised. With a 360-degree target engagement ability, the GLSDB provides commanders and planners with a flexible, precise and reliable guided weapon which complements existing ballistic-trajectory weapons.
Because it makes use of existing MLRS launchers, the GLSDB requires minimal additional investment. It also has a high Technology Readiness Level because both the main components of the weapon as well as the launch vehicle are proven, off-the-shelf products. Boeing has delivered the SDB to the US Air Force for many years, and Saab has a long history with many users of the M26 rocket motor. In the new GLSDB the two items are connected via an inter-stage adapter.
All-angle, all-aspect attack
For the commander in the field, the GLSDB allows the artillery system to reach targets from significantly longer distances and engage hard-to-reach targets. The weapon can hit targets 150 km in front of the launcher or circle back to attack a target up to 70 km behind it. There is no minimum distance. It can fly around terrain such as mountains to conduct reverse-slope engagements, and can defeat a range of targets, from hardened facilities to soft-skinned assets, using high or low angles of attack. It is accurate around one metre. It can launch from hidden or protected positions to avoid detection by enemy forces.
The MLRS launch vehicle normally carries two pods, holding up to six weapons per pod. Multiple rockets can be launched to act against multiple targets, with near simultaneous impact. The standard SDB weapon has a multipurpose penetrating blast-and-fragmentation warhead (with cave-breaching capability) and an integrated electronic fuze which is programmable for impact or delay fuzing to provide either deep penetration or accurate proximity height-of-burst. The warhead has a carbon-fibre case with a conical steel nose to minimise fragmentation.
There are also two variants. The Focused Lethality Munition (FLM) is an option for ultra-low collateral damage, while the Laser SDB provides moving-target capability.
The integrated inertial navigation system (INS) and global positioning system (GPS) provides guidance, navigation and position data for the bomb. The guidance section also incorporates a GPS receiver with anti‑jam capability, selective availability and an anti-spoofing module.
The companies have identified ten potential initial customers for the GLSDB.