Military

Miniature Munition Capability
Miniaturized Munitions Technology Demonstration (MMTD)

As of 07 January 1998 ACC approved a new acquisition strategy for the Small Bomb System (SBS) program. This strategy involves integrating the SBS on the F-22, F-22X and JSF and also includes combining the SBS and the Low Cost Autonomous Attack System (LOCAAS) efforts into a single program. This new program has been designated Miniature Munition Capability and had a planned start date for FY03. Implementation details of the new strategy are still being developed.

The goal of the predecessor Miniaturized Munitions Technology Demonstration (MMTD) effort was to produce a 250-pound class munition effective against a majority of hardened targets previously vulnerable only to 2,000-pound class munitions. Using personnel and experience gained from the GBU-28 "Bunker Buster" program and the Exploitation of Differential Global Positioning System for Guidance Enhancement (EDGE) programs, the MMTD test team completed development testing in 18 months. McDonnell Douglas was awarded a $6 million contract to assist in the design and development of the MMTD concept. After completing successful warhead (Jan 96) and system (Mar 96) CDRs, the warhead already demonstrated the objective of penetrating 6 feet of reinforced concrete.

A second phase which integrates terminal seeker and anti-jam GPS technology into the Phase I baseline weapon was planned for FY99-02 under the Miniature Munition Capability effort. Because of the short flight times (about one minute) the GPS receiver must have fast acquisition capability.

The guidance law will be designed to penetrate the target with an obliquity angle of zero degrees. There is however an obliquity angle tolerance of approximately 20 degrees; anything greater will not ensure case survivability. The angle of attack at impact is constrained to be zero degrees with a tolerance of one degree. This nulling of the angle of attack must be achieved at least one missile time constant prior to impact. In addition, the munition is required to penetrate with an impact velocity of at least 1100 ft/sec. Consequently, the guidance law will be designed to optimize terminal velocity subject to the aforementioned constraints. In order to maximize terminal velocity, the vehicle will fly in a coordinated bank-to-turn mode (as opposed to skid-to-turn). While this does increase the complexity of the flight control system, the advantage of increased speed and maneuverability outweigh the increased complexity. The control variables for the guidance law are angle of attack (or normal acceleration) and bank angle. The autopilot architecture will be designed to be robust to disturbances and plant uncertainties. In addition, the autopilot is required to track the angle of attack and bank angle commands from the guidance law while stabilizing the vehicle. This will require a robust autopilot methodology. Many modern design techniques, such as LQR/LQG, LQG/LTR, Mu-synthesis, can provide controllers which achieve the specified design requirements. Implicit in this is the need to gain schedule the designs with altitude, Mach Number, angle of attack or a combination thereof. Analysis of the stability and performance robustness will be performed to ensure meeting the guidance, navigation and control requirements.

The second generation SSB has an advanced warhead which is designed to maximize penetration capability without sacrificing blast/fragmentation potential. This is achieved by use of liners to control fragmentation and enhanced energetic explosives such as HMX or CL-20.

Light Attack Bomb is a follow-on demonstration for the Small Smart Bomb to expand the SSB target set by demonstrating maneuver capability against ground mobile targets using an existing seeker for guidance.

The High Leverage Munitions (HLM) concepts are a class of next generation weapons designed to efficiently package small, highly lethal mini missiles of the future. They employ direct dispense technology being developed under WL/MN Low Cost Dispensing (LODIS) program as a means of high density loadouts for both internal and external carriage. This low observable/low drag container is capable of incremental or salvo dispensing and has virtual interface capability. Air bags are used to eject the mini missiles. The dispenser serves as a shipping/stores container. Electrical interface to the mini missiles is made via a single 1553 bus.

The vision of the evolution of the program is that this first transition phase, Phase 0, will serve as a bridge to the formal acquisition program, which is envisioned to be a two-phased program to meet the warfighter's operational requirements. Phase 0 will first establish an evolutionary design and development approach for an SDB and carriage system effective against fixed/stationary targets and mobile/relocatable targets. It is also the intent during this phase to conduct a system level validation against a fixed and mobile/relocatable target. Upon approval to start a formal acquisition program, the objective of Phase 1 of the acquisition program would be to continue development and begin production of the fixed/stationary variant followed by the development and production of the mobile/relocatable variant during Phase 2. The intent is to award up to two contracts for Phase 0 system design of an SDB system to meet operational requirements against fixed/stationary and cued mobile/relocatable targets, with options for system fabrication, ground and flight tests, and ATR algorithm development.

References

• Miniaturized Munitions Capability Concept Study PRDA No. WMX-99-0001 - 07 October 1998
• ANNEX F Common Solution/Concept List (U) Air Force Mission Area Plan (MAP) [as of 11 July 1997 - Rev 10] - Detailed and comprehensive Air Combat Command descriptions of weapon system modernization efforts required to satisfy known needs.

• Miniaturized Munition Technology Demonstration Eglin Air Force Base