D. JOINT THEATER MISSILE DEFENSE

1. Definition Joint Theater Missile Defense (JTMD) is the capability to use the assets of multiple services and agencies to detect, track, acquire, and destroy enemy theater ballistic missiles and cruise missiles. It includes the seamless flow of information on missile launches by specialized surveillance capabilities, through tracking by sensors from multiple services and agencies, to missile negation or destruction.

The vision for a future JTMD architecture is shown conceptually in Figure IV.D-1. It depicts a theaterwide set of surveillance systems, multiple layers of defensive weapons systems, and a highly responsive C³I network to integrate the surveillance and weapon capabilities. The internetted set of surveillance systems depicted includes airborne, shipborne, and land-based radars plus space surveillance systems to detect launches of theater ballistic and cruise missiles and track them until they are successfully intercepted.

In this future JTMD architecture, the first of the defensive layers is boost phase intercept of ascending ballistic missiles by airborne and/or space-based high-power laser weapon systems, as shown conceptually in Figure IV.D-1. This boost-phase intercept layer offers a special contribution to deterring or defeating attacks by missiles armed with weapons of mass destruction (WMD) (chemical, biological, or nuclear warheads), because lethal warhead materials could fall on the attacker's own territory. For the next defensive layer, or upper tier, long-range interceptor missiles from land or shipboard launchers are depicted intercepting at high altitude the missiles that avoided boost-phase intercept. The final defensive layer, or lower tier, includes shorter range defensive missiles from land- or sea-based launchers to provide a final round of lower altitude terminal intercepts above the defended area. Similarly, cruise missiles detected by the surveillance sensors could be intercepted first by longer range sea- and land-based surface-to-air and air-to-air missiles and then by the shorter range terminal defense missiles.

JTMD capabilities are critical elements of the new operational concept of full-dimensional protection envisioned in Joint Vision 2010. The Theater Missile Defense Mission Need Statement defines the mission of JTMD as protecting U.S. forces, U.S. allies, and other important countries, including areas of vital interest to the U.S., from theater missile attacks. The JTMD mission includes the protection of population centers, fixed civilian and military assets, and mobile military units.

2. Operational Capability Elements

The four operational capability elements, or pillars, of JTMD are attack operations, active defense, passive defense, and command, control, communications, and intelligence (C³I). These are shown in Table IV.D-1.

This section focuses on the active defense pillar and those aspects of the C³I pillar that are unique to the JTMD mission. Capabilities for the attack operations pillar such as quick-response, precision strikes against mobile theater missile launchers are addressed in Section B, Precision Force. In addition, attack operations against WMD capabilities—including prompt attacks against WMD-armed theater missiles on the battlefield and counterforce attacks against hardened WMD storage and production facilities—are addressed in Section J, Counter WMD. Similarly, responsive, theaterwide command, control, communications, computers, and intelligence (C⁴I) systems and enhanced theater intelligence, surveillance, and reconnaissance (ISR) capabilities that support all theater operations (including JTMD) are addressed in Section A, Information Superiority. Finally, passive defense capabilities—including rapidly assessing and disseminating chemical and biological (CB) threat information and providing effective protection against CB attack for personnel and platforms—are described in Section I, Chemical/Biological Warfare Defense and Protection.

3. Functional Capabilities

The functional capabilities needed to support the four operational capability elements or pillars of JTMD are listed in Table IV.D-1. The detailed functional capabilities are grouped into those supporting the three functional areas of acquisition sensor, target intercept, and C³I.

In the acquisition sensor area, the four functional capabilities are detection, tracking, discrimination, and communications. Rapidly detecting theater missile launches and establishing current and accurate tracks for those missiles are essential for cueing the active defense against the attacking missiles. In addition, the detection, tracking, and communications functional capabilities strongly support passive defense by providing attack warning and impact point predictions to threatened areas. Those three functional capabilities also strongly support attack operations by accurately identifying missile launch locations so that the launchers can be promptly attacked. The discrimination functional capability to distinguish a ballistic missile warhead from accompanying missile components or fragments and decoys is essential for cueing the active defense to attack the right target. In addition, the attack characterization information about the missile type and potentially the type of warhead from discrimination sensors moderately supports both the attack operations and passive defense operational capabilities, as shown in Table IV.D-1.

In the target intercept area, the first three functional capabilities—lethality, footprint, and divert—specifically refer to capabilities of interceptor missiles (often called kinetic energy interceptors in contrast to directed-energy or laser intercept). The first, lethality, is the capability to effectively destroy the warhead payload of an attacking missile when the interceptor impacts the target (for hit-to-kill interceptors) or passes near the target and detonates a fragmenting warhead. The second function, footprint, is the capability of an interceptor missile to intercept targets over the required defended area because of its speed, range, and altitude performance capabilities. The related third function, divert, is the lateral acceleration capability of the interceptor missile to maneuver during the final phase, or end game of the intercept in order to impact the target or pass within the interceptor warhead's lethal envelope of the target.

The next three functional capabilities are the capabilities of the sensors on board the interceptor missile or laser weapon platform to: acquire the right target based on cuing and handoff information passed from acquisition sensors through the C³I system; discriminate between the target warhead and missile fragments or decoys; and maintain tracking of that target until the intercept is completed. The communications functional capability links the interceptor missiles or laser platforms to the acquisition sensor functional capabilities. The final target intercept functional capability is boost-phase intercept with laser weapons, either airborne or space based. As indicated in Table IV.D-1, because of the onboard acquisition sensor and communications capabilities envisioned for them, the laser weapon platforms would also support the C³I and attack operations operational capabilities by forwarding missile launch and tracking data they acquired.

The C³I area includes functional capabilities for high-capacity datalinks to rapidly pass acquisition sensor data; and for specialized waveforms to forward missile tracks among elements of the joint TMD forces. C³I also includes the functional capabilities of very-high-throughput data processing to capture, analyze, and disseminate the sensor data with minimum delays; and data fusion capability to synergistically combine tracking and discrimination data from multiple sensors of different types.

4. Current Capabilities, Deficiencies, and Barriers

Joint Theater Missile Defense includes a number of surveillance, weapons, and C³I systems that are currently deployed or under development by the services. The Ballistic Missile Defense Organization (BMDO) is responsible for the family-of-systems approach to ensure integration of these systems into a joint warfighting capability. Current theater C³I systems are being upgraded for interoperability, and future JTMD systems will be linked by interoperable C³I networks to provide joint connectivity.

Current JTMD capabilities are limited to terminal point defense missile intercepts at low to medium altitudes; there is no capability for upper tier intercepts at higher altitudes and longer ranges or for boost-phase intercept. However, higher performance missiles and surveillance systems now under development will extend intercept capabilities to the higher altitudes and longer ranges required for theaterwide upper tier missile defense. In addition, technology development and demonstration efforts are underway to establish the feasibility of laser weapons for boost-phase intercept, as will be described in Section 5.

The current capability for low-altitude, terminal point defense missile intercepts is based on the PATRIOT and HAWK interceptor missile and radar systems. PATRIOT upgrades, including software enhancements and improved fuzing, have increased engagement capability beyond the level available during Operation Desert Storm. The fielded PATRIOT system allows for rapid, accurate fire unit emplacement, remote launcher placement up to 12 km from the radar, and radar enhancements to improve theater ballistic missile (TBM) detection and increase system survivability. Upgrades to the lower altitude, shorter range HAWK system will yield a near-term defense capability for expeditionary forces through modifications to allow detection, tracking, and engagement of short-range TBMs.

To improve these lower tier defense capabilities, upgrades to both the Army PATRIOT and Navy missile systems are under development. The PATRIOT Advanced Capability 3 (PAC-3) version now under development will enhance PATRIOT system engagement performance by adding a new hit-to-kill missile interceptor with a millimeter-wave seeker and side-firing, divert propulsion thrusters for enhanced maneuverability during the final phase of intercepting a target. In addition, an upgraded version Block IV A of the Navy Standard Missile 2 (SM-2 Block IV A) is under development to provide a sea-based, lower tier interceptor capability. These upgraded PAC-3 and SM-2 Block IV A missiles will also provide improved intercept performance against cruise missiles. In addition, project definition and concept validation are beginning for the Medium Extended Air Defense System (MEADS), a highly mobile system to be deployed with maneuver forces to provide coverage against short-range TBMs, cruise missiles, and other aerodynamic threats.

However, these lower tier systems with moderate velocity missiles have only limited capability against longer range TBM threats with higher reentry velocities, particularly if the attacking missiles are fitted with WMD warheads. Chemical or biological warheads intercepted at low altitude could still disperse hazardous materials over defended areas, particularly if the warheads contained submunitions.

Therefore, upper tier TMD systems with high-performance interceptor missiles capable of defending larger areas and intercepting targets including WMD warheads at higher altitudes are under development for both land and sea basing. The Army Theater High-Altitude Area Defense System (THAAD) includes a new interceptor missile and a ground-based phased-array acquisition and tracking radar. The Navy Upper Tier Theater-Wide system includes a high-performance interceptor missile and upgrades to the AEGIS shipboard phased-array radar.

The characteristics of the land attack cruise missile threat present special challenges for the JTMD mission. Cruise missiles can fly at low altitudes to avoid detection, can maneuver unpredictably to evade intercept, and can be launched from both aircraft and mobile surface carriers, thus reducing the likelihood of prelaunch suppression. Furthermore, advanced cruise missile designs can have very low radar and infrared signatures that make the missiles very difficult to detect against low-altitude background clutter. Therefore, current surveillance systems and interceptor missiles have only limited capabilities to detect, track, and intercept cruise missiles.

In response to these limitations of current capabilities against cruise missiles, during FY96 the Cruise Missile Defense Phase I ACTD demonstrated the feasibility of the air-directed surface-to-air missile (ADSAM) concept for over-the-horizon engagement of cruise missiles. 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 links, and successful live-fire intercepts with SM-2 missiles and simulated intercepts with PATRIOT PAC-3 seekers were demonstrated. This ACTD was a significant step toward demonstrating the feasibility of concepts for the cruise missile defense component of JTMD.

For space surveillance capabilities beyond those available from the current Defense Support Program (DSP) infrared missile launch detection satellites, development of the Space-Based Infrared Systems (SBIRS), including both low- and high-altitude surveillance satellite constellations, is programmed.

Key limitations of current technologies that now preclude development of the functional capabilities needed to fully satisfy the JTMD goals are highlighted in the third column of Table IV.D-2, Goals, Limitations, and Technologies for JTMD. For example, for the target intercept functional capability, key limitations include discrimination of the actual target in the face of a sophisticated threat including decoys, tracking of maneuvering targets, lack of a current capability for boost-phase intercept, and the inability to defeat early-release submunitions.

Target maneuvering is another key limitation that imposes additional lateral acceleration and divert propulsion requirements on missile interceptor technology. Current TBMs may maneuver unpredictably during reentry because of missile dynamics or reentry vehicle asymmetries, and advanced reentry vehicles could potentially take evasive maneuvers, thus reducing the probability of successful intercept. Therefore, technologies that enhance interceptor maneuverability and improve interceptor probability of kill would allow a reduction in interceptor inventory and could significantly reduce JTMD costs.

Two other significant barriers for JTMD are sensor/data fusion and target signature data. Sensor fusion is a challenging technical barrier for TMD because fusion must take place in near-real time in order to be useful for guiding intercepts. Sensor data fusion is a technique in which multiple sensors provide individual data sets on targets and backgrounds, which are then processed into a single merged set of data. The fused data present a much more accurate picture of the battlespace to the field commanders than the sum of the individual data sets. The data fusion process occurs in one of three ways: (1) the fusion of data from several sensors on the same platform (e.g., a thermal imaging sensor and laser radar onboard an interceptor or a space surveillance satellite); (2) the transfer or handover of data from one sensor platform to another (e.g., target object map data handover from one surveillance sensor to an interceptor); or (3) the merging of track files recorded and processed from two or more geographically separated sensors (e.g., ground radar and space surveillance sensor data track files).

Availability of accurate target signature data is also a key barrier because successful TMD detections and intercepts, particularly hit-to-kill intercepts, require accurate and reliable target signatures. Threat signatures drive the designs of the detection and tracking radars and optical sensors and the seeker hardware selections. They also establish requirements for the supporting detection, discrimination, aimpoint selection, and kill assessment algorithms. The primary limitation on obtaining accurate signatures is generally the lack of access to the actual missile threats operating in their deployed environment. To compensate for this, BMDO supports a robust threat and signatures flight and phenomenology program where both simulated threats and acquired threats are flown and measured.

5. Technology Plan

Some of the key technologies needed to breach the limitations to achieving the JTMD functional capabilities and to enable the JTMD operational capability elements are shown in Figure IV.D-2. Most of these key technologies are being addressed by the technology development and demonstration efforts encompassed by the eight DTOs listed in Table IV.D-3 that are cited in this chapter as most directly supporting JTMD. In addition, as discussed in Section 2 above, related technology efforts described in other sections of this JWSTP also support JTMD operational capabilities: technology demonstrations under Precision Force (Section B) that support the JTMD attack operations capability, efforts under Information Superiority ( Section A) that support C³I capabilities applicable to JTMD, and technologies under Chemical/Biological Warfare Defense and Protection (Section I) that support the JTMD passive defense operational capability.

Technology development and demonstration efforts directly supporting JTMD are focused on the following four areas. First, enhance ground and airborne radar and space and airborne optical sensor capabilities to improve missile launch detection, tracking, and discrimination. Second, improve interceptor missile performance, including onboard discrimination and divert maneuvering capabilities for both exo- and endo-atmospheric interceptors. Third, demonstrate the feasibility of boost-phase intercept with airborne and space-based laser technologies. Fourth, increase the capabilities of theater C³I systems to rapidly process and transfer the massive amounts of sensor and tracking data required to support defensive intercepts.

In the area of enhanced surveillance, tracking, and discrimination sensor technologies, the three key DTOs are D.02, D.04, and D.05. Technology efforts under D.02, Integrated Sensor/Data Fusion Demonstration, will establish the feasibility of near-real-time sensor data fusion. D.04, Advanced X-Band Radar Demonstration, will develop new technology transmit/receive modules that could significantly increase the tracking and discrimination capabilities of the THAAD radar. The Advanced Space Surveillance DTO, D.05, includes technologies for advanced satellite sensors and subsystems that could be inserted into new and upgraded space surveillance systems, including the SBIRS.

Additional details on the seven DTOs that most directly contribute to achieving JTMD warfighting capabilities are given below. These DTOs directly support the four JTMD operational capability elements of attack operations, active defense, passive defense, and C³I, as presented in Table IV.D-4. The DTOs are structured to demonstrate incrementally increasing capability over time. These technology advances can potentially be inserted into JTMD surveillance, weapons, and C³I systems at the component and subsystem level to provide warfighting capability that incrementally increases over time. Full-page descriptions of the DTO technical content, milestone schedules, funding, and performing organizations are presented in the accompanying DTO volume.

• D.02 The Integrated Sensor/Data Fusion Demonstration is a series of experiments performed on the ground and on an aircraft, focusing on integrating a suite of novel optoelectronic sensors with a lightweight laser radar. These experiments use a state-of-the-art neural network image processor to perform high-speed sensor signal processing, and perform multisensor onboard sensor data fusion in real time, simulating a space- or UAV-based sensor platform with enhanced tracking and surveillance capability.

• D.03 The Discriminating Interceptor Technology Program develops and demonstrates in flight experiments the key technologies required to provide an exoatmospheric interceptor with the advanced discrimination capabilities required to distinguish a reentry vehicle from accompanying missile fragments and decoys. The key technologies include a two-color, long-wavelength infrared focal plane array and an active laser radar coupled to advanced data fusion algorithms and the compact, very-high-throughput processing required to perform reliable intercepts of complex, sophisticated target threat clouds.

• D.04 The Advanced X-Band Radar Demonstration will demonstrate a fivefold increase in the output power of solid-state transmit/receive (T/R) modules by exploiting advanced gallium arsenide and wide bandgap semiconductor device technologies and advanced monolithic microwave integrated circuit (MMIC) packaging technologies. This advanced T/R module design could directly replace the current module design in the THAAD phased-array ground-based radar (GBR). This upgrade would increase detection range by approximately a factor of two and would improve sensitivity for discrimination by a factor of five, thus greatly enhancing the THAAD GBR's capabilities for JTMD.

• D.05 The Advanced Space Surveillance DTO includes development of innovative technologies for key space surveillance subsystems. These technologies include advanced multiband (ultraviolet plus infrared) focal plane arrays, gigabyte-per-second laser communications, image data fusion algorithms and processors, high-efficiency spacecraft solar panels, and high-performance satellite electric propulsion. These technologies could be incorporated into the programmed space surveillance system development programs (SBIRs) or integrated and demonstrated in a subsequent flight experiment.

• D.08 The Atmospheric Interceptor Technology DTO includes development and demonstration at the prototype component level of several key technologies that would be required for a hypersonic hit-to-kill missile for intercepts within the lower atmosphere. The challenge of discriminating between actual reentry vehicles and decoys or missile fragments is partially alleviated for such endoatmospheric intercepts because atmospheric drag strips away lighter decoys and fragments. Under this DTO, prototypes of a strapdown infrared seeker and an externally helium-cooled missile forebody with an optical window will be developed. Development of other missile components and flight demonstrations could potentially be conducted under an augmented or follow-on program.

• WE.04.04 The Airborne Lasers for TMD DTO develops the technologies for boost-phase intercept using a high-power laser beam from an airborne platform. Technologies from efforts supporting this DTO are now being incorporated into the design for the demonstration phase of the Air Force Airborne Laser Program, which is scheduled to conduct an airborne lethality demonstration against a ballistic missile target by FY02. Advanced technologies subsequently developed under this DTO will then be incorporated into the design for the engineering and manufacturing development phase of the Airborne Laser System. Technologies under development include advanced target tracking and atmospheric compensation using adaptive optics to achieve laser beam propagation over long paths through the upper atmosphere. Advanced chemical laser technology to increase the efficiency and reduce the laser weight and size for aircraft installation is also being developed.

• WE.41.04 The Multimission Space-Based Laser DTO is demonstrating the technologies for high-power space-based laser systems that could be used for boost-phase intercept of TBMs as well as against longer range missiles and other targets. This DTO integrates a high-power chemical laser designed for space operation with a laser beam director and tracking components in a lightweight, flight-representative ground test configuration. This integrated ground demonstration will establish the engineering basis for a potential follow-on space demonstration at 25 to 50 percent of the scale that would be required for an operational space-based laser weapon system.

The schedules for key technology efforts supporting these DTOs and the relationships among the technology efforts and DTOs are depicted in Figure IV.D-3.

In addition to the seven DTOs cited above that exclusively or primarily support JTMD, there are other DTOs in the DTAP that are advancing technologies important to future JTMD capabilities. For example, for space-based surveillance systems detecting TBMs against the earth background, the complexity and variability of the background clutter are key limitations for detecting dimmer missile targets. Therefore, the development, validation, and demonstration of advanced background clutter algorithms and prediction codes under the Satellite Infrared Surveillance Systems Backgrounds DTO (SE.56.01) are crucial for future JTMD space surveillance systems. From the same Sensors, Electronics, and Battlespace Environments technology area of the DTAP, the technologies for dual-band, cooled infrared focal plane array (FPAs) and highly uniform, uncooled FPAs that are being developed under DTAP DTO SE.33.01, Advanced Focal Plane Array Technology, support and are closely integrated with efforts under the JWSTP DTOs D.02 and D.03.

From the same technology area, radiation tolerant and hardened microelectronics technologies from DTO SE.37.01, High-Density Radiation-Resistant Microelectronics, will be needed for some JTMD surveillance systems and interceptor missiles facing natural space radiation and potential nuclear weapon environments. Processing analog signals from FPAs in surveillance sensors or on interceptor missiles to detect dim targets against complex backgrounds or digitizing radar signals to detect cruise missiles in ground clutter requires very high resolution, high-speed analog-to-digital converter technology from this technology area. Similarly, the technology efforts under DTAP DTO SE.27.01, Microwave SiC High-Power Amplifiers, complement the advanced transmit/receive module technology efforts under JTMD DTO D.04. Finally, efforts under the photonics thrust DTOs SE.35.01, Optical Processing and Memory, and SE.36.01, Photonics for Control of Radio Frequency Signals, support key technology needs in lasercomm, high-speed optical datalinks, solid-state nonvolatile memory, and high-capacity computer interfaces under the JTMD C³I Operational Capability Element (Table IV.D-2).

6. Summary

The incremental advances in demonstrated technology available to support JTMD warfighting capabilities are depicted in Figure IV.D-4. The dates shown in the figure are the timeframes in which JTMD technologies are projected to have been successfully demonstrated based on ongoing or programmed technology development and demonstration efforts; they are not the timeframes in which operational systems incorporating those technologies would be deployed. Once the technology demonstrations are completed, the technologies are expected to be sufficiently mature and the engineering risk sufficiently low that those technologies could be incorporated into the designs for modifications to deployed systems or into new systems. Development, production, and deployment of those operational systems incorporating the advanced technologies would require additional time and funding. For some technologies that could be retrofitted at the component or subsystem level as modification kits into systems already deployed, the development and upgrade period could be relatively short. However, for other technologies that would require major modifications to systems already deployed or in development or that would require development of new systems, the time from a technology demonstration milestone to a deployed operational JTMD capability could be many years.

By FY 2001, enhanced surveillance, acquisition, tracking, and discrimination capabilities against TBMs will be accessible by exploiting the technologies demonstrated under the Integrated Sensor/Data Fusion Demonstration and the advanced X-band T/R module program. Next, the initial demonstration of boost-phase intercept of a ballistic missile is scheduled for FY02 under the Air Force's Airborne Laser program using technology developed under the Airborne Lasers for TMD DTO.

Beyond FY04, robust JTMD capabilities—including advanced space-based surveillance, boost-phase intercept by airborne and space-based lasers, and onboard discrimination for both exo- and endo-atmospheric interceptors—will become attainable from the technology demonstrations under the surveillance, laser, and advanced interceptor DTOs, as shown in Figure IV.D-4. As depicted conceptually in Figure IV.D-1 at the beginning of this section, such a robust future JTMD architecture would provide a full theater defense against ballistic and cruise missiles that would include over-the-horizon targeting and tracking of TBM launches, precision targeting of land attack cruise missiles, TBM intercept above the atmosphere by exoatmospheric interceptors with superior discrimination capability, and high endoatmospheric intercept of TBMs.