Directed Energy Lethality Assessments of Hypersonic Threats

The fast-paced, ever evolving threat from global adversaries and our ongoing effort to counter those threats is perhaps best represented today through the advent of the hypersonic-based weapons, where ōhypersonicö is defined as a vehicle that flies Mach 5 or faster and spends most of its time in the atmosphere. Directed energy weapons (DEWs), such as high-powered microwave (HPM) or high energy laser (HEL) weapons, are an area of active research due to the advantages of electromagnetic energy over more traditional kinetics-based concepts. For example, DEWs travel at the speed of light thus having the ability to adjust quickly to any adversarial maneuvering. They can have adjustable power to either deter, damage, or destroy. Finally, DEWs have the potential for lower cost per shot with virtually unlimited firing power, depending purely on the robustness of the power source. The biggest disadvantage is that any flow disturbance through the optical path can cause boresight or tip/tilt errors, blurring, and reductions in optical signal strength (Strehl loss), all of which reduce the ability to accurately place as much energy on target as possible. DEWs have been successfully demonstrated in defending against subsonic targets (mostly drones). But fielding a DEW for supersonic or hypersonic threats is considerably more complicated due to high-speed flow effects (shocks) as well as high energy of the flow. Experiments in the hypersonic regime are expensive and often do not match flight conditions (duration, test article size, etc.) while flight tests are even more expensive. Therefore, there is a need to develop simulation tools that can render the hypersonic flight environment to the accuracy required to predict the aero-optical/electromagnetic losses, assess the effectiveness of energy on target, and to determine lethality. The proposed innovation is to provide an automated tool by which the location and energy on target from a DEW can be estimated and probability to kill (Pk) assessed. To accomplish this goal, two technical objectives are presented. The first entails the development of simulation tools to accurately predict the hypersonic flow environment in which aero-optic/electromagnetic wave propagation errors and losses will be assessed. The second is to assess the lethality of physically destructive HEL sources through high-fidelity flow simulations performed on deformed/damaged vehicles that consider both aerodynamic and thermodynamic effects. As these high-fidelity simulations can be computationally expensive, Artificial Intelligence/Machine Learning (AI/ML) algorithms, trained using high-fidelity simulations, will be used to catalog lethality based on damage location, degree of damage, flight conditions, etc. and provide an instant assessment of Pk. Various methodologies will be explored to achieve these objectives to select the most feasible for the Phase II effort. Approved for Public Release | 24-MDA-11906 (16 Sep 24)