Remote Quality Measurement of Deployable Collectors and Structures

Solar Thermal Propulsion (STP) is becoming an increasingly viable alternative to chemical propulsion upperstage. The STP technologies are nearing the flight experiment stage of development. During a STP flight experiment, it will be desirable to evaluate the accuracy of the deployment and quality of the solar concentrator(s). This proposal describes a measurement system based on digital photogrammetry that will be designed to meet these objectives. In Phase I, a baseline system will be modified to operate remotely in the vacuum environment of the AFRL SPEF chamber at Edwards AFB. The system will be capable of measuring the position and orientation of an inflatable solar concentrator and its support structure with respect to the desired focal plane. The system will also be capable of measuring the shape error of the collector directly; and through a conversion algorithm and optical ray trace code, the slope error of the collector will be determined. The system will be demonstrated during a deployment test of STP hardware in the SPEF chamber. In Phase II, the system built in Phase I will be used as the baseline for a flight design of a measurement system to be used on an upcoming Spartan bus STP flight experiment.