PATRIOT ANTI-CRUISE MISSILE (PACM)
A further development, designed to counter threats from cruise missiles, is the Patriot Anti Cruise Missile (PACM), which is a PAC-2 missile with a dual mode seeker, adding an active radar seeker to the existing TVM guidance. The net result was the development of an effective, affordable ACM capability as a by-product of the Patriot system ATBM upgrades. This upgrade would provide the Army with a potential alternative to significantly improve the performance of the fielded Patriot weapon system against stressing cruise missiles.
In September 1998 Congressional conferees reaffirmed their support for fully evaluating the Patriot anti-cruise missile (PACM) concept and directed the Secretary of the Army to complete a rigorous test and evaluation program in fiscal year 1999, using funds previously appropriated for this purpose, to determine the effectiveness of the PACM seeker against the full range of cruise missile threats. Results of this evaluation shall be provided to the congressional defense committees in a report by April 15, 1999. The report shall also include an assessment of options and associated costs for utilizing the PACM seeker in future upgrades to existing Patriot missiles.
The Fiscal Year 2000 budget request included no funds for development or production of the Patriot anti-cruise missile (PACM) upgrade system. The Senate bill would authorize $60.0 million in Missile Procurement, Army, for longlead materials land initiation of a low-rate initial production program of 200 PACM modification kits. The House amendment would authorize the budget request.
The conferees supported development and testing of the PACM seeker. S. 1059 - National Defense Authorization Act for Fiscal Year 2000 included a $60 million authorization for the Patriot Anti-Cruise Missile (PACM) program to begin production following two successful flight tests. The Department did not request funding for and does not support the bill's provision for PACM, for which the Army does not have an operational requirement.
The conferees noted the conclusion of the Army's April 1999 report to Congress, which indicated that, based on extensive ground testing, "the performance of the PACM design has been demonstrated." The conferees also note that the first PACM flight test appears to have been successful. The conferees directed the Secretary of the Army to complete the PACM flight test program using funds previously appropriated for this purpose.
Based on information obtained from the PACM ground and flight test program, the conferees directed the Secretary of Defense to assess the capability of the PACM missile to counter cruise missiles, including low-observable cruise missiles, compared to the capability of the Patriot PAC-3 missile and other upgraded versions of the Patriot missile to counter such threats, and the opportunity costs of PACM acquisition. In preparing this assessment, the Secretary was to utilize the Defense Science Board. If, based on the findings of this assessment, the Secretary determined that production of PACM missiles is warranted during fiscal year 2000, up to $35.0 million of funds authorized to be appropriated in Missile Procurement, Army, may be made available to retrofit and improve the current inventory of Patriot missiles in order to meet current and projected threats from cruise missiles. The Secretary was to submit a report on his assessment and recommendations to the congressional defense committees by March 15, 2000.
The Defense Science Board Task Force on Patriot Anti-Cruise Missile (PACM) met in closed session on February 1, 2000. At this meeting, the Task Force reviewed and compiled recommendations for the Secretary of Defense on how to best respond to the Congressional directive to assess the capability of the PACM to counter cruise missiles, including low- observable cruise missiles, compared to the capability of the Patriot PAC-3 missile and other upgraded versions of the Patriot missile to counter such threats, and the opportunity costs of PACM acquisition.
The FY2001 budget request contained no funds for PACM procurement. The final DSB report indicated that between $100 and $125 million of research and development funding were needed to complete PACM design, resolve parts obsolescence, prepare facilities for production, integrate PACM with Patriot ground elements, and complete ground and flight testing. The DSB also indicated that the cost to upgrade PAC 2 airframes to the PACM configuration was about $1.0 million per missile. The House Armed Services Committee believed that, even if ground- and flight-testing needed to make an informed judgment on the technical merits of the missile were complete, the costs identified by the DSB would still be prohibitive. For these reasons, the committee recommended no funds for PACM procurement, as requested.
The Army's Patriot Anti-Cruise Missile (PACM) program was completed in 1999 with two successful flight tests (direct hits) against stressing cruise missile threats. Raytheon conducted the first flight and intercept test of the missile on 19 July 1999, and resulted in a successful intercept of an MQM-107 sub-scale target flying at low altitude. The flight test culminates a three year technology program to counter emerging cruise missile threats with an upgrade to existing PAC-2 and prior missiles. Raytheon Company conducted its second successful flight test in two attempts of the Patriot upgrade for anti-cruise missile capability. The 10 September 1999 test at the White Sands Missile Range, N.M., resulted in a successful intercept of a BQM-74E sub-scale target flying at low altitude to simulate a cruise missile threat. The fire unit used the most current version of Patriot ground equipment and software to support the test.
The Patriot system upgrade being developed will result in the world's most capable medium range air defense system. It is designed to buy back battlespace lost to recent developments in the air breathing and tactical ballistic missile (TBM) threat. The upgrades also reflect lessons learned in Desert Storm in defending against TBMs in combat. Although driven by the TBM threat, the upgrades include responding to another lesson learned in Desert Storm - the effectiveness of cruise missiles against ground targets.
In designing the anti-TBM (ATBM) upgrades, it became apparent that an effective anti-cruise missile (ACM) capability could be obtained at little additional cost. The features needed for ATBM - better acquisition and track performance, improved discrimination and identification capability, bigger footprint, better lethality - resulted in system improvements that provide significantly better capability against cruise missiles. This improved ACM capability was recognized early and the system upgrades were tailored to take advantage of this additional benefit.
Evolving threats, including weapons of mass destruction delivery systems, require a more robust Patriot interceptor. This needed capability can be achieved through low-risk modifications to existing PAC-2 fielded Patriot missiles. These modifications, all contained in the missile forebody, re-use the missile's propulsion and control sections, resulting in a low-risk, cost-effective upgrade requiring no hardware modifications to the Patriot Ground Equipment. The modifications include a Ka-band active seeker integrated with the Patriot C-band semi-active seeker, a four-nozzle thruster to provide fast airframe response divert capability, and a lethality-enhancing "aimable" rod warhead.
The seeker was developed under PACM. This seeker approach preserves the standard Patriot C-band operation, thus maintaining Patriot's demonstrated capability against all enemy electronic countermeasure (ECM) tactics, while simultaneously adding the benefits of a high resolution active seeker. This combination results in a highly robust performance against all current and future threats.
The four-nozzle thruster provides thrust during the terminal phase of flight. Actuator control of the nozzle valves control the thrust around the missile body, resulting in very fast response divert capability. Prototype units were built and successfully ground tested in 1994. The tests included simulated operations with the missile subsystems and validated both the thruster design and the interfaces with the missile. The thruster unit replaces the Patriot blast fragmentation warhead and leaves sufficient volume and weight for the rod warhead.
An "aimable" kinetic energy rod warhead is the final modification to the Hit-to-Kill missile configuration. This warhead has been designed by Raytheon to significantly increase the achievable lethality resulting from a direct hit intercept that misses the optimum location for submunition "kill." Based on completed ground tests against simulated submunition warheads, a rod warhead has been configured that is compatible with the allocated weight and volume available in the 16-inch diameter Patriot airframe.
These modifications are achieved without changing the volume or weight of the fielded Patriot missile, or any hardware interfaces with any ground equipment, resulting in a very low-risk, low-cost integration into the Patriot Fire Unit. Performance predictions resulting from this spiral development process using the validated, highly accurate Patriot system simulation, modified to include the thruster and rod warhead parameters, have been completed. These results predict a very high level of achieved lethality over a significantly expanded engagement zone against all current and future airbreathing, Cruise Missile and TBM threats in either a benign or ECM environment.
The Army Mountain Top Experiment further explored how to take advantage of this by demonstrating beyond line-of-sight engagement capability. Under this ACTD, radars on a mountaintop site simulating airborne radars were used to detect and track missiles that would have been over the horizon for ground- or sea-based radars. Engagement data were transmitted to interceptor missiles via the Navy's Cooperative Engagement Capability (CEC) links, and successful live-fire intercepts with SM-2 missiles and simulated intercepts with Patriot PAC-3 seekers were demonstrated.
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