Search

The role of Failure Response Advisor (FRAd) is to identify the relevant information and to use it to compute the severity of faults and repair times. Advanced Caution and Warning System (ACAWS) modules for diagnosis and system effects identify faults and impacts and deliver that information to the Planner. The Planner gathers information about activities from an Activity Dictionary. The role of the planner in FRAd is to detect violations in the resources required to perform the set of planned activities. This information includes what resources are needed for given activities to be performed. The Planner correlates fault and impact information with its effect on activities to be performed and delivers the correlated information (Activity Effects) to the Reasoner. The Activity Information Repository, contains the activity information required by the Activity Dictionary and additional timing information required by the Reasoner. Additional information on faults is contained in a Fault Table and is delivered, as needed, to the Reasoner that computes fault severity, repair timing suggestions, and provides the advice to be published on the User Interface. The role of the Reasoner is to compute both proposed timing information for repair activities and to provide a value of Severity based on the number and criticality of the activities blocked by given faults and the functional failure of all impacted components. The concept of Severity is quantitative, based on the number and Criticality of activities blocked by the failure.

This NASA Glenn innovation is a novel multi-junction photovoltaic cell constructed using selenium as a bonding material sandwiched between a thin film multi-junction wafer and a silicon substrate wafer, enabling higher efficiencies. A multi-junction photovoltaic cell differs from a single junction cell in that it has multiple sub-cells (p-n junctions) and can convert more of the sun's energy into electricity as the light passes through each layer. To further improve the efficiencies, this cell has three junctions, where the top wafer is made from high solar energy absorbing materials that form a two-junction cell made from the III-V semiconductor family, and the bottom substrate remains as a simple silicon wafer. The selenium interlayer is applied between the top and bottom wafers, then pressure annealed at 221°C (the melting temperature of selenium), then cooled. The selenium interlayer acts as a connective layer between the top cell that absorbs the short-wavelength light and the bottom silicon-based cell that absorbs the longer wavelengths. The three-junction solar cell manufactured using selenium as the transparent interlayer has a higher efficiency, converting more than twice the energy into electricity than traditional cells. To obtain even higher efficiencies of over 40%, both the top and bottom layers can be multi-junction solar cells with the selenium layer sandwiched in between. The resultant high performance multi-junction photovoltaic cell with the selenium interlayer provides more power per unit area while utilizing a low-cost silicon-based substrate. This unprecedented combination of increased efficiency and cost savings has considerable commercial potential. This is an early-stage technology requiring additional development. Glenn welcomes co-development opportunities.