Tech Briefs

Photogrammetry System and Method for Determining Relative Motion Between Two Bodies

Highly accurate, flexible system measures relative dynamics in six degrees of freedom.NASA’s Langley Research Center has developed a novel method to calculate the relative position and orientation between two rigid objects using a simplified photogrammetric technique. The system quantitatively captures the relative orientation of objects in six degrees of freedom (6-DOF), using one or more cameras with non-overlapping fields of view (FOV) that record strategically placed photogrammetric targets.

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Directed Design of Experiments for Validating Probability of Detection Capability of a Testing System

NASA’s Langley Research Center has developed new software that enables users of critical inspection systems to validate the capability of the inspection system. Traditionally, inspection systems are validated using various methodologies to determine probability of detection (POD). One widely accepted metric of an adequate inspection system is that there is 95% confidence that the POD is greater than 90% (90/95 POD). Directed Design of Experiments for Probability of Detection (DOEPOD) is a user-friendly software package that enables detailed analysis of 90/95 POD or at any specified confidence level. Although it was designed to validate the capability of inspection systems to find fracture- critical flaws in materials, DOEPOD can be applied to systems to locate any type of flaw as well as to validate the detection capability of personnel. DOEPOD can also be employed as the core of an NDE (nondestructive evaluation) system, and provide accurate on-demand validation of the inspection system.

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Method and Apparatus for Measuring Surface Air Pressure

This technology enhances the predictive capabilities of weather forecasting models.NASA’s Langley Research Center has developed a novel method for long-range atmospheric pressure sensing. Based on known properties involving oxygen density, the technology is able to measure small pressure changes over a wide area. NASA developed the technology to address known gaps in the area of weather forecasting as a result of the inability to accurately detect atmospheric pressure above the ocean. Oxygen band reading can be performed remotely, most likely from a satellite-based system. The technology is particularly applicable in the area of storm forecasting.

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HEIST Ironbird to Test Cutting-Edge Hybrid Electric Propulsion Technologies

Testbed will study the system complexities of powering an aircraft with two different power sources.A key goal of NASA’s aeronautics research is to help the aircraft industry transition to low-carbon propulsion. Many potential power architectures for electric propulsion have been proposed, and design considerations for turbo-electric distributed propulsion have been studied. However, few mid- to full-scale testbeds have been built to validate these different architectures.

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Saturn Net Flux Radiometer (SNFR)

A Saturn Net Flux Radiometer (SNFR) is being developed as part of a payload for a future NASA-led Saturn Probe Mission. The current design has two spectral channels i.e., a solar channel (0.4-to-5 μm) and a thermal channel (4-to-50 μm). The SNFR is capable of viewing five distinct viewing angles during the descent. Non-imaging Winston cones with window and filter combinations define the spectral channels, each with a 5° field-of-view. Un - cooled thermopile detectors are used in each spectral channel and are read out using a custom-designed Application Specific Integrated Circuit (ASIC). The SNFR measures the radiative energy anisotropies with altitude. In the solar channel, the downward flux will determine the solar energy deposition profile and the upward flux will yield information about cloud particle absorption and scattering. In the thermal channel, the net flux will define sources and sinks of planetary radiation. In conjunction with calculated gas and particulate opacities, these observations will determine the atmosphere’s radiative balance.

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Applying the Dynamic Inertia Measurement Method to Full-Scale Aerospace Vehicles

Researchers have begun testing on large articles in conjunction with ground vibration tests.Researchers at NASA’s Armstrong Flight Research Center have been interested in using the Dynamic Inertia Measurement (DIM) method on full-scale aerospace test vehicles, given its advantages over traditional methods for determining the mass properties of such vehicles. Developed at the University of Cincinnati, the DIM method uses a ground vibration test setup to determine mass properties using data from frequency-response functions. The method has been successfully tested on a number of small-scale test articles — including automobile brake rotors, steel blocks, and custom fixtures — but until now, has had limited success being tested in larger applications. Armstrong’s recent efforts, in conjunction with ground vibration tests, represent a step forward in applying the DIM method successfully to full-scale aerospace vehicles.

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Modules for Inspection, Qualification, and Verification of Pressure Vessels

This automated, modular, standardized system features interchangeable probes.After decades of composite over-wrapped pressure vessel (COPV) development, manufacturing variance is still high, and has necessitated higher safety factors and additional mass to be flown on spacecraft, reducing overall performance. When liners are used in COPVs, they need to be carefully screened before wrapping. These flaws can go undetected and later grow through the thickness of the liner, causing the liner to fail, resulting in a massive leakage of the liner and subsequent mission loss.

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