UBC Theses and Dissertations
Space weather and the MOST microsatellite Skaret, Kristina A.
The MOST (Mcrovariability and Oscillations of Stars) microsatellite is designed to obtain the most precise stellar photometry (AL/L -10 ⁻⁶) ever achieved. In preparation for the launch of the first satellite devoted to asteroseismology, a complete evaluation of space weather in the baseline orbit including radiation analysis is performed, providing a 'weather forecast' for the mission in order to assist the MOST instrument team with crucial planning decisions. Results of assessing the effects of space weather include recommendations for the choice of orbit, design structure, operating guidelines, and data reduction guidelines. This analysis has aided the MOST team to convince the Canadian Space Agency (CSA) to identify a launch vehicle capable of taking MOST to a polar sun-synchronous orbit. Preliminary shielding recommendations have been incorporated into the mechanical design of the telescope. Estimates of the amount of degradation the CCD will experience, including the number of Single Event Effects (SEEs, effects caused by interaction with a single cosmic ray), have influenced current operating procedure guidelines. It is shown that radiation doses to the CCD are not expected to cause critical failure of the detector. A minimum mission lifetime is established for a worse-case radiation environment and found to be of sufficiently long duration to meet all primary scientific objectives. As the impact of the radiation environment (and other orbital environment related factors) is less than critical thresholds, the forecast for the MOST microsatellite looks 'sunny and warm'.
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