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Anomalies are unexpected conditions that occur in a functional engineering system. They must be detected, diagnosed and resolved in order to maintain the system in its functional role. Managing anomalies in space systems is particularly challenging given their complexity and their remote orbital environment. In this article, we describe our recent work in extending first principles reasoning approaches for the broad types of anomalies often encountered in complex space systems. We also describe the software algorithms we've developed to implement this approach. In addition, we review our new efforts to integrate these algorithms with industry-standard system modeling environments such as Matlab/Simulink and Satellite ToolKit. We also describe how the resulting processing system is being incorporated into the mission operations network that has been fielded by Santa Clara University and which is used to manage a variety of university-class and research-grade small satellite mission). This network includes a centralized mission control complex in the Space Technology Building in the NASA Ames Research Park in Moffett Field, California. The network also includes a set of geographically distributed communications stations. These stations are operated remotely via the Internet, employ amateur and unlicensed frequency bands, and use tracking antennae such as an OSCAR-class dual Yagi antennae or a 60-foot parabolic antenna. Finally, we review our initial results from using this reasoning system while conducting mission operations. This work includes on-orbit results for the Sapphire spacecraft (launched in 2001), interaction with a hardware-in-the-loop lab-based satellite simulator, and preparatory development and testing for several spacecraft to include the NASA Genesat-1 satellite, the two-satellite U.T Austin FASTRAC mission, and the Santa Clara University ONYX onboard autonomy demonstration satellite. |
