AGM-131A SRAM II / Advanced Air-to-Surface Missile [AASM]
Discussion of a replacement for the SRAM missile began in August 1982 with the Air Force Chief of Staffs order to terminate the SRAM Motor Modification program which was to extend the useful life of the SRAM rocket motor. In July 1983, the Defense Resources Board approved the Advanced Air-to-Surface Missile [AASM] as a fiscal year 1986 major system new start. While the fiscal year 1986 budget was the first to specifically request funds for the AASM program, Congress approved a reprogramming action of fiscal year 1984 funds for system definition studies on September 20,1984.
During 1982 and 1983, the Strategic Air Command started drafting a Statement of Operational Need. Prior studies such as the Counter Soviet Union Airborne Warning Control System, Advanced Strategic Air Launched Missile, and the SRAM Longer Life Motor Modification did not specifically address Statement of Operational Need requirements.
In March 1983 the first program manager, a major in the Aeronautical Systems Division of the Air Force Systems Command, was appointed. Prior to that and shortly after initiation of the program, Systems Division staff working with the contracting officer began developing a preliminary AASM cost estimate to secure program approval. They completed the preliminary AASM cost estimate, but aircraft integration costs were omitted because sufficient data was unavailable at the time.
In January 1984 the project office issued the system deflmtlon study request for proposal to eight aerospace contractors. Only three -- Boeing, Martin Marietta, and McDonnell Douglas -- submitted proposals. Contracts were awarded to these three firms in February 1985. The system definition contracts will form the basis for defining alternatives for performance characteristics, logistical concerns, full-scale development milestones and planning cost estimates for development and production. The studies will include a defense penetration analysis and generation of system design characteristics: weight, shape, signature, speed, flight trajectory, materials, propulsion, and guidance.
DOD reduced the fiscal year 1985 request by $26 million to $28.4 million and Congress approved $3 million less, or $25 million for fiscal year 1985. Of the $25 million, only $12.4 million was released to the Air Force. The program manager stated that the fiscal year 1986 request of $128 million was reduced by DOD to $78.9 million and Congress approved only $35 million. Because of these changes, the missile's initial operational capability would be delayed from fiscal year 1991 to 1992. Imtial operational capability is defined as having five B-1B alert aircraft fully loaded with the new missile.
According to the December 31, 1985, Selected Acquisition Report, the cost including development and procurement was estimated at $2.23 billion for 1,633 missiles (in fiscal year 1983 dollars). Until September 1985, the Air Force planned to carry two contractors through the critical design review step of the full-scale development phase; based on what the Air Force sees as the low risk nature of the program, the traditional demonstration/validation phase was omitted. Because of funding constraints, the plan to have two contractors through critical design review was eliminated. As of April 1986, the plan called for having one contractor for the entire full-scale development phase.
AGM-131A SRAM II
During 1985, the AASM program was renamed the Short Range Attack Missile II (SW II) Program.
This missile is a short-range, self-guided nuclear weapon designed during the Cold War but canceled before production. The air-launched AGM-131 SRAM II (Short Range Attack Missile) had a range of 250 miles and carried a single warhead yielding 200 kilotons. Full-scale development began in 1987, and the SRAM II was to be operational in 1993. Like the SRAM, the SRAM II was to provide the B-1B and the Advanced Technology Bomber with a supersonic, low-radar-cross section, air-to-ground nuclear missile that can attack fixed and defended targets, and neutralize enemy terminal defenses such as surface-to-air missile sites.
The President terminated the programs on 27 September 1991. At the time of the President's announcement, the Air Force was in the process of negotiating a restructuring of the program because the contractor (Boeing Aerospace and Electronics) could not meet the provisions of the original contract,
The US Air Force proposed to use White Sands Missile Range (WSMR) for the Development Test and Evaluation flight testing of the Short Range Attack Missile (SRAM II) on B1-B aircraft. A total of 16 live launch tests and up to 25 captive carry flights would have been scheduled for WSMR over a 27 month period from February 1992 through May 1994. All carrier flight tests would launch and recover at Edwards Air Force Base, California. Five of the 16 tests would contain radioactive depleted uranium. All live launches would impact at either the Salt or Mine target site at WSMR.
The AGM-131 was approximately has 2/3 of the size of the AGM-69. In this way a B-1B coould carry up to 36 of the newer missile, against 24 of the older AGM-69. The General Dynamics FB-111 was to be able to carry six missiles internally.
A main SRAM II feature was its warhead. Designed to be safer to store than earlier models, it used "insensitive high explosives" to trigger its nuclear reaction. These and other improvements reduced the danger of accidental plutonium dispersal in case the missile was involved in an aircraft fire or the SRAM II's rocket motor overheated. The SRAM II program, however, was ended in 1991 as part of a U.S. arms control initiative, and because of production problems with the missile's motor.
The airframe was largely built of composite materials. The SRAM-II was planned as a stealthy design, like it's future launchers. Like the SRAM, this missile too had a trio of low-aspect control surfaces at the extreme end of it's fuselage. The body had a squared off hump along it's center and rear to accommodate the electronics, chiefly the Litton laser ring-gyro based INS based on the latest VHSIC (Very High-Speed Integrated Circuit), which formed the guidance system for the missile. Propulsion was to be supplied with an advanced Hercules solid-propellant rocket motor giving one boost stage and at least two sustain stages.
ATK is one of the leading developers of pulse motor technology. The company began developing pulse motors in 1978 with the Radial Pulse Motor Advanced Development Program (RPMADP). Since then the company has developed a wide variety of motors, from the Rattler (4-in. dia x 8.6-in. long) to the SRAM II (15.3-in. dia x 125-in. long). In addition, the company has developed both two- and three-pulse designs. The SRAM II was designed as a lighter, less complicated rocket motor with greater range and reliability than its predecessor, the SRAM-A. The SRAM II was 15.3-in. dia x 125.0-in. long and incorporated an IM7 graphite composite case, a styrene butadiene rubber (SBR) thermal barrier, two radially burning HTPB propellant grains, carbon-carbon nozzle throat, titanium breechlock and aft closure/nozzle shell, and R-181 wound elastomeric insulation (WEIT). Although the SRAM II successfully demonstrated the viability of the propulsion system through 24 motor firings, the program was cancelled in 1991 by presidential order as part of the START II treaty between the U.S. and Russia.
The SRAM II missile was being developed to strike hardened and defended targets from outside enemy defenses to enhance bomber survivability. As a result of development problems, the projected range and accuracy capabilities of the SRAM II had been degraded. Details regarding projected accuracy were classified, but the reduced range capabilities were due to the loss of rocket motor thrust, caused by problems with the rocket motor propellant, and the missile's maneuverability limitations. Numerous changes had been made in an effort to increase the range. Among those changes were a weight reduction, movement of the center of gravity, a change in the nose slope to reduce drag, and a delayed motor ignition to allow longer coasting before the second of the two-pulse rocket motor ignited.
In spite of these changes Boeing still could not meet the range requirements specified in the contract and therefore, proposed reductions to the SRAM II ranges, Additionally, the Strategic Air Command (SAC) significantly reduced its required ranges as part of a review of its overall strategic requirements. SAC's reduced range requirements for the SRAM II essentially mirrored the ranges being achieved by the SRAM A--the missile the SRAM II was intended to replace. Boeing's proposed ranges would have met SAC's revised requirements.
At the time of program termination, the SRAM II schedule had slipped about 4 years since 1985. The first assets to be delivered--that is, 50 SRAM II missiles and 5 B-1B aircraft modified to carry the SRAM II --were initially scheduled for March 1992, However, that milestone had slipped to December 1995. The estimated unit cost of SRAM II had nearly doubled, from $0.8 million to $1.4 million, and the quantity of missiles to be bought had decreased by about 57 percent, from 1,633 to 700 missiles.
The warhead development programs for the SRAM II (W89) and SRAM T (W91) were compatible with missile development schedules. In response to a request from the Assistant to the Secretary of Defense for Atomic Energy, the Air Force and the Department of Energy had completed a study in June 1991 to determine the feasibility of replacing the W69 warhead on the SRAM A missile with the W89 warhead that was being developed for the SRAM II. The study concluded that, while there were technical risks in using the SRAM A missile due to its age, the W89 warhead baseline design could be incorporated on the SRAM A.
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