NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 X4.03-9959
SUBTOPIC TITLE: Inspection and Diagnostics
PROPOSAL TITLE: On-orbit health monitoring and repair assessment of thermal protection systems

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
2525 Arapahoe Avenue / Bldg. E4 #262
Boulder, CO 80302-6746

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Dr. Robert B. Owen
2525 Arapahoe Avenue / Bldg. E4 #262
Boulder, CO 80302-6746

This SBIR project delivers On-orbit health MoNItoring and repair assessment of THERMal protection systems (OMNI_THERM). OMNI_THERM features impedance-based structural health monitoring (SHM) and uses miniaturized autonomous sensor/actuators to diagnose damage and verify repair efficacy.

Implications of the innovation
Thermal protection systems are crucial for crew safety. New techniques of on-orbit monitoring and assessment of thermal protection structures are needed for space exploration. An autonomous impedance-based SHM system is one of the few viable solutions; however, this technique has not been applied to thermal protection systems.

Technical objectives
OMNI_THERM deploys autonomous, wireless, self-powered sensor/actuators that harvest energy from vibration and thermal gradients. Each sensor/actuator is a complete SHM system and reports independently; this computationally distributed framework minimizes single points-of-failure. We have built a prototype, performed SHM on launch support structures, and demonstrated repair assessment.

Research description
Phase I demonstrates OMNI_THERM SHM on reinforced carbon-carbon (RCC) and other model structures. Phase II includes miniaturization and expands OMNI_THERM capabilities to additional thermal materials, hybrid structures, and advanced composites.

Anticipated results
Phase I establishes feasibility by detecting cracks, gouges, and stress-induced defects in RCC and other model structures and verifying repairs. Phase II delivers an OMNI_THERM system tailored to on-orbit SHM and repair assessment.

The Exploration Systems Enterprise will develop and use increasing sophisticated hardware and systems. Sustainable and flexible space exploration requires reliable structural assessment on-orbit and in-flight to guide hardware maintenance and servicing and verify repair efficacy for complex structures. Thermal protection systems directly support crew safety and are among the most crucial structural elements. These complex structures and materials must withstand severe stresses and hostile aero-thermo-chemical environments. They are also vulnerable to micrometeor damage and must be continuously monitored and repeatedly reassessed. Lightweight, compact, and reliable SHM technology is needed to autonomously inspect and diagnosis advanced thermal protection systems.

Commercial applications include Homeland Security structural analysis to mitigate threats (preparedness) and assess damage (response), smart structures, and SHM of nuclear plants, aircraft, dams, and bridges. SHM is an emerging industry driven by an aging infrastructure, malicious humans, and the introduction of advanced materials. Government customers include the Federal Highway Administration and the Departments of Defense, Transportation, and Energy. Non-government customers include oil and gas companies, and other crucial-structure custodians. Westinghouse Electric Company (Nuclear Services Division) is our commercialization partner. WEC sees OMNI_THERM applications in nuclear power plants, and provides engineering and marketing support at no cost.