High Speed Systems Test (HSST)
Abstract
The HSST project continued to advance ground and flight test technologies, techniques, instrumentation, and modeling and simulation capabilities required for the development of hypersonic weapon systems. In FY 2023, HSST continued to address critical technology shortfalls for hypersonic test and evaluation in aerothermal and propulsion ground testing capabilities and advanced instrumentation to support hypersonic flight tests. Several other technology development efforts also progressed throughout the year. To address the technology shortfall involving aerothermal and propulsion testing, HSST is developing a new test facility that utilizes clean-air heat addition (non-vitiated air) and a variable Mach number nozzle (VMN) capability to provide the representative high-temperature conditions for characterizing weapon systems, including air-breathing propulsion capabilities. The clean-air heat addition is especially important to the characterization of air-breathing propulsion systems, as previous HSST efforts demonstrated that vitiated air provides different gas properties than clean air found in the atmosphere and thus is not representative of what the vehicle would experience in flight. This significantly affects the engine’s operation in the test environment and results in erroneous predictions of performance in flight. Additionally, characterization of advanced seeker/sensor systems for hypersonic systems also benefits from clean-air heat addition as it provides a more representative environment for the system to operate in. The variable Mach number capability provides a more representative trajectory simulation for the system under test, permitting more accurate predictions before conducting flight tests. Assembly of the new test facility, called the Hypersonic Aerothermal and Propulsion Clean-Air Testbed (HAPCAT), was completed in FY 2022, enabling initial facility checkouts in FY 2023. All of the efforts associated with HAPCAT also serve as pathfinders for the development of a larger-scale, more capable facility at the AEDC. To address quality of flight simulation deficiencies and capacity constraints involved with aerothermal material characterization ground testing, HSST continued new aerothermal test technology development efforts to prototype alternative high enthalpy test technologies. This includes the advancement of inductively-coupled plasma ground test facilities and hypersonic wave heated ground test facilities that can serve as a complement to arc-jet heater capabilities. The SkyRange capability is an unmanned aerial vehicle-based range to support hypersonic flight tests and other missions for the Department of Defense. SkyRange provides a more agile, flexible, and cost-effective method for providing support to long-range hypersonic flight tests with increased data collection capabilities beyond the current state-of-the-art. It also addresses a critical throughput shortfall for supporting the number of hypersonic flight tests required, as a sufficient number of instrumentation assets does not exist. RQ-4 Global Hawks (RangeHawks) and MQ-9 Reapers (RangeReapers) comprise the platforms used for SkyRange, taking advantage of their long-endurance, flexibility, and high-payload capability. SkyRange augments existing air, sea, and land test support assets referred to as the “string of pearls,” reducing the high costs associated with traditional flight test support and increasing mission flexibility. Novel sensor suites are being developed in the areas of telemetry capture and relay, multispectral imaging, atmospheric sensing, terminal scoring, and other areas to aid in the development of hypersonic systems. Several of these sensors are being developed through HSST for integration into the SkyRange capability. Achievements were made for both SkyRange aircraft platforms in FY 2023. SkyRange telemetry systems supported multiple missile flight test events on both the Pacific and Atlantic ranges, demonstrating the ability to rapidly deploy, from a central location, to any flight test range that is required. RangeReapers were modified with telemetry systems integrated onto the aircraft. A new adaptive phased-array telemetry system was delivered and has been integrated onto a RangeHawk for initial testing late in FY 2023. The program continued to establish a central hub for mission support in Grand Sky, North Dakota, while continuing to develop several forward operating locations for flight test support. Block 20 and Block 30 modifications to RQ-4 aircraft converting them into Rangehawk configuration was also initiated. RangeLynx module development was completed in FY 2022 and installation was completed on RangeReapers in FY 2023, providing real-time, secure satellite-based telemetry and data relay to ground stations and other SkyRange assets. Progress continued on the development of a high-fidelity multispectral imaging tracking system for integration onto an RQ-4 Global Hawk as part of the SkyRange capability. Fabrication was completed and a critical fit-check of the one of a kind prototype system on a RangeHawk was successfully executed. Integration and ground testing was ongoing during FY 2023. A high-altitude laser based atmospheric measurement system in FY 2023. The software to operate this system on a RangeHawk was completed. The first RangeHawk system is being fabricated after passing critical design review in FY 2022. This system provides never-before-obtained critical atmospheric measurements (such as temperature, pressure, and wind speed) along the path of hypersonic missiles during flight test. The data is required to evaluate missile performance during flight. Flying testbeds have the potential to support a wide range of RDT&E activities from basic research to acquisition programs by providing opportunities to mature hypersonic technologies in flight test on shorter schedules with and smaller costs than previously available. An effort, the Multi-Service Advanced Capability for Hypersonics-Test Bed (MACH-TB) is active and have progressed through requirement gathering and design reviews in FY 2023. The MACH-TB effort completed its first and second flight tests in FY 2023, demonstrating sub scale and full scale launch platform testbed capability. Additional upgrades and technology development continued at the CUBRC hypersonic shock and expansion wind tunnels to support hypersonic ground testing. The new hypersonic wave heated facility (HWF) construction continued with manufacturing of the full-scale facility components based on successful operation of the prototype facility. This facility will provide important capabilities for aero-optic and aerothermal ground testing required for hypersonic weapon system development.
Document Details
- Document Type
- Accomplishment
- Publication Date
- Oct 01, 2025
- Source ID
- 6aae20a3763c1be6575e89f8b26f7c12