LGM-30 Minuteman III Modernization
As a result of U.S. initiatives to cancel development programs for new intercontinental ballistic missiles and retire the Peacekeeper ICBM, Minuteman will become the only land-based ICBM in the Triad. To compensate for termination of the Small ICBM and Peacekeeper Rail Garrison programs, DOD will conduct an extensive life extension program to keep Minuteman viable beyond the turn of the century. These major programs include replacement of the aging guidance system, remanufacture of the solid-propellant rocket motors, replacement of standby power systems, repair of launch facilities, and installation of updated, survivable communications equipment and new command and control consoles to enhance immediate communications.
The focus of the Department's efforts are to extend the life of the MM III weapons system until 2020 while beginning the requirements process for the next-generation ICBM. A comprehensive set of sustainment programs are planned or underway:
- Guidance Replacement Program (GRP)
- Propulsion Replacement Program (PRP)
- Propulsion System Rocket Engine (PSRE) life extension program ("replaces aging components in the post-boost vehicle")
- Rapid Execution and Combat Targeting (REACT) service life extension program
- Environmental Control System (ECS)
- Safety Enhanced Reentry Vehicle (SERV) program
The Rapid Execution and Combat Targeting (REACT) equipment modification was installed in a total of 50 Minuteman III Launch Control Centers at F.E. Warren AFB, WY; Malmstrom AFB, MT; and Minot AFB, ND; with a Final Operational Capability date of 31 July 1996. All modified sites are presently on operational alert status. Key features of the modification program include: reduction of retargeting time by 50 percent, integration of Launch Control Center Command & Control and Higher Authority Communications, automation of routine functions to reduce crew workload, increased crew survivability, replacement of obsolete Command & Control and Higher Authority Communications equipment, and implementation of two-level maintenance.
The Minuteman III Guidance Replacement Program (GRP) consisted of a five-year engineering and manufacturing development (EMD) program. The program requirement is to extend the service life of the Missile Guidance Set (MGS) beyond the year 2020 by replacing aging parts/assemblies with current, high reliability technology while maintaining the current accuracy performance. During FY96, the system Preliminary Design Review (PDR) and a number of component critical design reviews were successfully conducted. Engineering Models (EM) of the MGS were built and tested to identify design weaknesses prior to the critical design review, and to lower the risk in the operational models used for qualification testing and initial operational test and evaluation. EM testing was also conducted at the Intercontinental Ballistic Missile (ICBM) Strategic Missile Integration Complex (SMIC) to verify compatibility with the actual missile hardware interfaces. GRP is also upgrading electronics in the Minuteman III MOD 7 telemetry wafer.
On 16 September 1998 the Minuteman III Guidance Replacement Program (GRP) successfully completed a second flight test from Vandenberg AFB. This second and final program development flight test further validated the end-to-end operational capability of the ICBM with the upgraded guidance system. The first flight test was conducted on 24 June 1998, and was found to meet or exceed all operational requirements. Following lift-off from Vandenberg AFB the missile traveled approximately 4,200 miles to the Kwajalein Missile Range. The flight test program followed successful completion of more than two years of rigorous ground testing conducted at government facilities in Albuquerque NM, Ogden UT and Vandenberg AFB and the Boeing facility in Anaheim CA.
Full-rate production began in 2000 with a total of 652 units being produced to support 500 operational Minuteman III ICBMs. The upgraded guidance system low rate initial production (LRIP) efforts were initiated in March 1998, with award of the LRIP contract to Boeing. Guidance hardware build efforts commenced at Boeing's El Paso TX manufacturing facility; where all previous GRP engineering and operational model hardware was built. Honeywell, a teammate on the program, conducts program production and test activities at its site in Clearwater FL. The first operational guidance systems were delivered to the Air Force in early 1999, ahead of the contract schedule.
After seven flight tests with the modified guidance system, the Air Force found that accuracy results were not in agreement with expectations. Accordingly, the Air Force conducted a supplemental accuracy investigation that identified two primary sources of error in the guidance system software. One source was erroneous implementation of computational precision. In some navigation calculations, truncation was implemented where round-off was intended. In some guidance calculations, better approximations were needed to maintain adequate precision. The other primary error source was a small, undesired residual velocity bias introduced into the calculations that govern the attitude of the re-entry vehicles at deployment. The Air Force initiated corrective actions though an Accuracy Upgrade Program (AUP). To date, the Air Force has conducted a total of four NS-50 flights with the AUP corrections, two in each of FY02 and FY03. The downrange biases observed previous to the AUP modifications appear to have been corrected. Additional NS-50 flights will be conducted in accordance with the FDE program. DOT&E will continue to monitor the results of this program.
In December 1995, the Minuteman Propulsion Replacement Program (PRP) was declared an Aquisition Category IC program. The program requirement is to extend the service life of the current Minuteman III rocket motors through 2020. All three stages underwent successful preliminary design reviews which updated the development specifications necessary to achieve the program requirements. Additionally, the Stage 1 rocket motor fabrication processes were demonstrated. The Stage 2 motor was successfully fired with new insulation materials, including environmentally friendly propellant manufacturing processes. The Stage 3 motor demonstrated its first design changes in a static firing at the Arnold Engineering Development Center rocket motor test facility. PRP also experienced a major challenge in FY96. The sole producer of a key propellant ingredient had an event at their facility causing the loss of their manufacturing capability. The program developed several options to find a new source of the material or to demonstrate the feasibility of another material.
The ICBM Team successfully tested a 33.4 year old Minuteman Stage 1 motor at the Utah Test and Training Range on February 24, 1999. LMS and Thiokol personnel in support of the Minuteman Stage 1 aging surveillance program conducted the static test, designated AS-16. Motor performance was very much as expected and even met motor specification requirements designed for Production Quality Assurance (PQA) motors. This 33.4 years old motor was the oldest Stage 1 motor ever tested. This test was the last of a series of 16 aging surveillance tests of Stage 1 motors conducted since 1994. The next aging surveillance test of an operational Stage 1 motor is scheduled for the year 2005.
The Minuteman MEECN Program (MMP) will replace the aging Survivable Low Frequency Communications System (SLFCS) in the Minuteman (MM) Launch Control Centers (LCCs) with an integrated Extremely High Frequency (EHF) and Very Low Frequency/Low Frequency (VLF/LF) communications capability. As the newest link in the Minimum Essential Emergency Communications Network (MEECN), this effort will provide the LCCs with the ability to receive Emergency Action Messages (EAMs) in the EHF and VLF/LF spectrum and send force reportback messages over EHF. For the MM LCCs this will include integration into the Higher Authority Communications/Rapid Message Processing Element (HAC/RMPE) processor. Missile Procedure Trainers (MPTs) and Minuteman Enhanced Procedures (MEPs) trainers as well as the development/maintenance systems will be modified to reflect changes to the ICBM operational system. Performance requirements for this program are specified in the ICBM LCC EHF System (ILES) Operational Requirements Document (ORD), the VLF/LF Communications Capability for the ICBM LCCs ORD, and the MMP ORD Addendum. The ISST and AFSATCOM systems will stay intact until deactivated by AFSPC.
In order to meet warhead levels set by START II, the United States has decided to permanently DEMIRV Minuteman III missiles from their current capability to carry up to three reentry vehicles to a newly configured single reentry vehicle system once the treaty enters into force. "Downloading" Minuteman III missiles from three reentry vehicles to one lowers the military value of each missile; reduces the likelihood of any country expending resources to preemptively attack America's ICBM force; and decreases the probability of future US leaders being force into a "use or lose" position. For a downsized force of 500 single reentry vehicle Minuteman III to continue to be an effective deterrent force, the guidance replacement program will improve the needed accuracy and supportability that is inherent in a smaller missile force. Peacekeeper missiles will be deactivated by 2003, provided START II is ratified and enters into force. Ultimately, a total of 500 single RV Minuteman IIIs will be the nation's ICBM deterrent force through 2020.
The Safety Enhanced Reentry Vehicle [SERV] program consists of modifications to existing hardware and software to accommodate the MK21/W87 RV on the MMIII weapon system. These modifications consist of the following: changes to weapon system software, changes to the RS to accommodate RV mounting, guidance hardware changes, and changes to support equipment (SE). The program will replace the MK12/W62 and MK12A/W78 (RV's) with a single MK21/W87 RV on 350 missiles. The remaining force will consist of 150 single MK12A's.
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