{"project":{"acronym":"","projectId":14673,"title":"Hot Ground Vibration Tests","primaryTaxonomyNodes":[{"taxonomyNodeId":10941,"taxonomyRootId":8816,"parentNodeId":10938,"level":3,"code":"TX14.3.3","title":"Thermal Protection Analysis","definition":"Thermal protection analysis encompasses the numerical approaches to simulate the incident environments as well as the material thermal and structural response to those environments. Such analyses can be performed via a range of approaches from fully uncoupled to fully coupled depending on mission requirements.","exampleTechnologies":"Aeroheating (convective and radiative), ablation, thermal, thermo-structural, coupled, margin policy development, reliability assessment, failure analysis, computational materials design","hasChildren":false,"hasInteriorContent":true}],"benefits":"
Ground vibration tests or modal surveys are routinely conducted to support flutter analysis for subsonic and supersonic vehicles. However, vibration testing techniques for hypersonic vehicles are not as well established due to the thermoelastic interactions that can occur when high-temperature materials are incorporated into a hot structure that contains metallic components. The thermoelastic interaction between those materials can affect the hypersonic flutter analysis. In recent years, numerous high-temperature materials, new fabrication technologies, and sensors have been explored for hypersonic vehicle applications. This research team is working to develop a high-temperature modal survey to expand the research database for hypersonics and improve the understanding of such dual-material interactions.
Work to date: NASA Armstrong directed a program to test a Carbon-Silicon Carbide (C/SiC) Ruddervator Subcomponent Test Article (RSTA) to support hypersonic material research. The RSTA has undergone numerous thermal, thermal-mechanical, and thermal-vibration tests. This research team conducted three modal surveys involving the RSTA to characterize the thermoelastic interaction of the hot-structure control surface. The team obtained good modal data at lower temperatures, but the off-the-shelf, high-temperature accelerometers malfunctioned on the hotter region of the test article. The experiments yielded test data that will be useful for future work and launched a high-temperature accelerometer development effort.
Looking ahead: The research team has obtained custom-made and multiple other high-temperature accelerometers and are taking steps to understand, evaluate and characterize their complexity and functionality in preparation for future thermoelastic vibration tests.
Benefits
Applications
The Armstrong Flight Research Center is NASA’s primary center for atmospheric flight research and operations, with a vision “to fly what others only imagine.” We believe that flight validation and research is one of the crucial phases within the advancement of any NASA technology, and it is often the barrier to technology utilization by the private sector. We also believe that aerospace technology can be enhanced through flight early in the Technology Readiness Level (TRL) lifecycle. In fact, some research can be done only in flight. The CIF projects are examples of aerospace technologies that are theoretically advantageous but have had little TRL advancement or are at too early of a technology level for support through a NASA mission.
The focus for the program is on validating, developing, and testing new and innovative technologies.
The current technology areas for the projects included:
AFRC is currently looking into following Technical Capability areas (not in any priority order and not all inclusive):
1. Small launch Space Systems
Develop small launch space systems such as horizontal rockets that could launch to orbit small free-flying space platforms (e.g., cuestas, nanosats, picosats).
2. Altitude Compensating Rocket Systems
Design, build, and test altitude compensating rocket systems or sub-systems designed to operate the rocket efficiently across a wide range of altitudes. Subsystems such as Altitude Compensating Nozzles are being considered.
3. Aero Gravity Assist Systems
Design, build, and test an Aerogravity assist system which uses a close approach to the planet, dipping into the atmosphere, so the spacecraft can also use aerodynamic lift to further curve the trajectory.
4. Launch Vehicle and Spacecraft Adaptive Controls
Develop and test adaptive controls architectures specifically tailored for application to launch vehicles. Adaptive Controls for launch vehicles would include unique features of the aerospace vehicle, such as control-structure interaction, propellant slosh, sensor performance, and actuator dynamics. In addition, the analysis, verification, and flight certification framework for the control system must be addressed.
5. Autonomous Systems
AFRC is exploring concepts for advanced autonomous systems and collaborative autonomous operations that could be applied across aerospace vehicles to enhance effectiveness, survivability, and affordability.
6. Autonomy in a Safety Critical Framework
Armstrong Flight Research Center is interested in the flight demonstration of high level autonomy in a safety critical framework with applicability to man-rated air and space vehicles. This high level of autonomy is enabled through the use of multiple sensor platforms and algorithms with high computational demands. Increased computational capability through embedded high performance computing and implementation of resource efficient algorithms is needed to support this integration. Research into embedded high performance computing using multi-core processors, FPGA, GPU, DSP and associated development of toolchains and algorithms targeted to these platforms is needed in order to reduce the Size, Weight, and Power (SWaP) of the flight vehicles..
7. Space Weather Systems
Design, develop, and test measurement systems to provide the capability for on-demand, validated, and archived radiation measurements related to human tissue and avionics silicon upset concerns.
8. Electromagnetically Boosted Rockets
One possible solution is to use an electromagnetic linear motor boost system to supplement the use of first stage booster rockets and rocket clusters. China Lake is currently advocating to NAVAIR to initiate a study of long term capital costs and recurring system operational costs of the use of an electromagnetic linear motor booster system for their rocket sled tracks as compared to the long term operational system costs of moving to a newer line of booster rocket production.
","parentProgram":{"acronym":"CIF","active":true,"description":"
Through the Center Innovation Fund, the Space Technology Mission Directorate allocates a small portion of the NASA workforce and procurement budget to internal research and development to feed early stage innovation in technology and exploration. Activities with in the Center Innovation Fund are proposed and led by NASA scientists and engineers. These activities and creative initiatives pursue emerging technologies that leverage talent and capabilities at the NASA Centers.
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