Atmospheric Interceptor Technology (AIT)

The objective of Atmospheric Interceptor Technology (AIT) was to develop and demonstrate advanced lightweight technologies for hypersonic HTK intercept of threat missiles within the atmosphere and integrate these technologies into a small (130 cm3), lightweight (50 kg) KV. High velocity intercepts are essential to maintain sufficient battle space, lethality, and coverage/footprint performance. However, such conditions provide severe aero-optic, aerodynamic, aerothermal, and structural requirements. Jet interaction (JI) testing is providing insights into JI sensitivities to design.

The development of the advanced kill vehicle in the BMDO Atmospheric Interceptor Technology (AIT) program was critical to the BPI program of the mid-1990s. The AIT program had its roots in the successful HEDI program which demonstrated the principle of hypersonic target acquisition and tracking in the atmosphere. Leveraging off past investments in cooled window technology, lightweight thermally protected structures, strapdown seekers, miniaturized electronics, and lightweight gel propellant divert and attitude control systems provide a lightweight kill vehicle with the capability of performing hypersonic, hit-to-kill intercepts of ballistic missile targets in the endoatmosphere. Combining this kill vehicle with the ASAS rocket motor technology from the LEAP program could permit the high velocity flight at low altitudes necessary for the BPI system.

Patterned after the LEAP development strategy, the AIT program was initiated in 1991 to address the kill vehicle design requirements of operating within the atmosphere (below 70 kilometers) at high velocities. This strategy resulted in a robust kill vehicle technology development program to support future TMD requirements to counter the potential evolution of the threat to enhance performance. AIT kill vehicles expanded on the legacy of lightweight integrated vehicle technologies developed in the LEAP program and hypersonic atmospheric ballistic missile target acquisition and tracking technologies developed in the HEDI program.

AIT was a technology testbed program to develop component technologies that could be applied to current acquisition programs as part of a P31 program. The payoffs of AIT technology were substantial: providing technical solutions to theater missile defense interceptor capabilities for contingencies and against advanced threats not addressed by the TMD systems programs and reducing technical risks and costs in support of current acquisition programs through direct technology insertions.

The goal of AIT was to revolutionize the development of endoatmospheric interceptors. The technology was designed to perform intercepts from the low atmosphere up through the low exoatmosphere, all at much higher velocities and performance than existing and past systems. These technologies not only decreased size and weight of the KV, but also allowed for increases in battlespace, coverage or footprint performance and lethality. This provided the warfighter with multiple fire control options in employing the optimum battlefield engagement strategies. Significant AIT technology advancements included: cooled window/forebody, strapdown seeker, solid propellant divert and attitude control system (DACS) and a lightweight integrated vehicle.

These kill vehicles incorporated cooled windows, strapdown seekers, miniaturized electronics, thermally protected structures, and lightweight gel propellant divert and attitude control systems to provide the capability to perform hypersonic hit-to-kill intercepts of ballistic missiles in all phases of their flight trajectories in both the exo- and endoatmosphere. The program completed cooled window development and fabrication, window aero-thermal testing based on component technology investments in 1990.

By 1993 the Atmospheric Interceptor Technology (AIT) program (formerly Endo LEAP) was focused on demonstrating strapdown seekers and strapdown guidance for very small miss distance intercepts at very high velocities against ballistic missiles within the atmosphere. This was being accomplished by advancing state- of-the-art technologies for small, lightweight, highly integrated kinetic energy kill vehicles (KV). Ground testing cannot fully duplicate the simultaneous interaction of the severe aerodynamic, aerothermal, and aero-optical conditions of hypervelocity flight within the atmosphere. Therefore, flight testing was required to fully validate the integrated technologies.

The electro-optical (ISO) flight testing can be broken down into two major elements: component flights and intercept flights. The component flights are utilized to resolve critical issues which will enable intercept flights, gather phenomenology data, and validate (ISO) window concepts. In the intercept flights, prime contractor KV's were to be flown against representative targets to demonstrate hit-to-kill (HTK) with aimpoint selection on the target lethal package. Initial studies indicated that both types of flights can be implemented utilizing boosters, launchers, and the organizational framework of existing interceptor systems.

By 1993 the Ballistic Missile Defense Organization (BMDO) was involved in the acquisition and upgrade of several missile systems that operate within the atmosphere. The Army THAAD, PATRIOT, ERINT, ARROW, Corps SAM, GBI, the Navy Sea Based TMD, the Air Force Boost Phase Interceptor (BPI), and the National Laboratories Hypervelocity Missile (HVM) were all atmospheric missile systems playing an important role in the BMDO program.

These high speed atmospheric missile systems are an integral part of the present and future ballistic missile defense systems that will defend the United States and its allies against ever increasing and disbursed threats. In order to economically suppon these systems in providing an effective defense capability. A coordinated technology base which develops atmospheric interceptor technologies was essential. This robust technology base provides the hedge against advanced threats, provides the enabling capability to increase missile performance, and reduce deployment risk as component replacement opportunities arise.

BMDO's AIT program was the technology base to be leveraged to provide the necessary upgrades to a vareity of systems. The objective of the AIT program is to develop. design, fabrimate and test lightweight hypersonic aanospheric technologies to support advanced ballistic missile interceptors. There were several elements to the AIT program. These elements involve prime contractor effons to design and fabricate EO and millimeter wave (MMW) seekers and highly integrated KV's. Broad Area Announcement (BAA) contracts concentrating on EO and MMW component technologies, extensive ground testing of these concepts, and finally flight testing of the components and the KV's.

The goal of the program is to integrate these technologies into a 25-30 kilogram experimental KV that demonstrates hypervelocity HTK within the atmosphere. The HTK must also be within a specified aimpoint radius on the target. The components and KV's are required to operate at these design points. The lower altitude design points are accomplished with direct ascent interceptors. The highest altitude and faster velocity design points are accomplished with lofted trajectory interceptors.

By 1995 the Endo-Atmospheric Interceptor Technologies Program was a comprehensive approach to coordinate the development and demonstration of advanced components critical for small, lightweight (less than 20KG) high velocity (4km/s) interceptors. The aero-thermal and aero-optical issues associated with hyper velocity flight in the atmosphere are being resolved. Advanced window materials and cooling techniques are being developed and tested. This enables interceptor velocity, lethality and overall performances to exceed the current low velocity interceptor flight capability. These technologies will provide the basis for strategic and tactical ballistic missile interceptors and Boost Phase Interceptors operating within the atmosphere. Seeker detailed designs had been completed and prototype seeker fabrication was initiated by 1995.

By 1997 AIT was demonstrating the advanced lightweight interceptor technologies required to achieve hit-to-kill on a precise aimpoint with the target body, thus ensuring the highest kill probability for all warheads. The AIT technologies, integrated into a modular KV design, incorporate the best ideas from numerous technology programs conducted over the previous decade.

In July 1997 USAF Lieutenant General Lester L. Lyles, Director, Ballistic Missile Defense Organization, provided direction to begin aligning AIT more closely with technology intsertion and P3I for TMD systems such as THAAD, NTW, MEADS, and Boost Phase Intecept. The Atmospheric Interceptor Technology (AIT) program became a technology integration program to exploit advances in kill vehicle technology to counter more complex threats.

Lyles specifically directed that AIT be planned and conducted with BMDO, Navy, Army and Air Force cooperation to make maximum use of existing Service infrastructures and to ensure that AIT is responsive to the needs of our current TMD acquisition programs. As part of this process, the Army and Navy in particular have provided information about their requirements in order to ensure AIT meets the needs of its primary end users.

The AIT program was not the development of a new system per se, but rather a technology testbed. In this approach, BMDO used the AIT program to develop component technologies which could be applied to current acquisition programs as part of a pre-programmed product improvement program. The AIT program is designed to provide: new capabilities with reduced costs and risks compared to current interceptor weapons systems, and enhancements to other interceptors under development; reduction of technical risks and costs in support of current acquisition programs through direct technology insertions; and technical solutions to provide theater missile defense interceptor capabilities for contingencies and against advanced threats not currently addressed by the TMD system programs.

By 1998, AIT has made excellent progress in developing component and subsystem technologies that support high velocity interceptors. MT was continuing to implement its strategy of developing and validating components and integrated subsystems through extensive ground testing and simulation activities and then providing the technologies for infusion into multi-service system applications.

On 21 September 1998 Raytheon Missile Systems Co., Tucson, Ariz., was awarded a $2,000,000 increment of a $45,711,321 (base year total) cost-plus-award-fee/fixed-fee contract, with a cumulative total of $345,165,038, if all options are exercised. The contractor will develop an Atmospheric Interceptor Technology (AIT) Interceptor Testbed, in support of the Ballistic Missile Defense Organization initiative that aligns AIT program requirements and technology efforts to meet future customer needs; and will be required to define, design, develop, fabricate, integrate, document, and test interceptor testbed components culminating in demonstrations of an integrated AIT interceptor testbed. Work will be performed Elkton, Md. (32%); Dallas, Texas (26%); Clearwater, Fla. (12%); East Aurora, N.Y. (9%); Biddeford, Maine (9%); Tewksbury, Mass. (6%); and Huntsville, Ala. (6%), and is expected to be completed by June 21, 2001. Contract funds will not expire at the end of the current fiscal year. There were 50 bids solicited on March 6, 1998, and two bids were received. The contracting activity is the U.S. Army Space & Strategic Defense Command, Huntsville, Ala. (DASG60-98-C-0061).

On 22 March 1999 Boeing North American Inc., Electronic Systems & Missile Defense, Anaheim, Calif., was awarded a $1,021,995 increment as part of an $8,200,000 cost-plus-fixed-fee letter contract for Atmospheric Interceptor Technology (AIT) Advanced Master Frequency Generator (A-MFG). This is a producibility improvement effort to provide an A-MFG to the Patriot Advanced Capability-3 (PAC-3) Project office suitable for insertion into PAC-3's full rate production program. The program will focus primarily on reducing the cost of the current MFG without degrading performance. Work will be performed in Anaheim, Calif., and is expected to be completed by April 30, 2001. Contract funds will not expire at the end of the current fiscal year. This is a sole source contract initiated on Nov. 4, 1998. The U.S. Army Space & Strategic Defense Command, Huntsville, Ala., is the contracting activity (DASG60-99-C-0004).