Molecular Contamination Assessments Of Hinode Optical Telescope Assembly During First Half Year
- Paper number
IAC-07-C2.6.01
- Author
Mr. Fumitaka Urayama, Space Engineering Development Co., Ltd., Japan
- Coauthor
Mr. Yoshio Watanabe, Japan
- Coauthor
Mr. Kei-ichi Yano, Japan Aerospace Exploration Agency (ISTA/JAXA), Japan
- Coauthor
Ms. Naoko Baba, Japan Aerospace Exploration Agency (ISTA/JAXA), Japan
- Year
2007
- Abstract
Spacecraft-induced molecular contaminants, such as outgassing molecules emitted from the organic materials, can deposit onto the critical components and degrade their thermo-optical properties. Based on ground-based tests and molecular contamination numerical analyses, these contaminants must be controlled to prevent the adverse impacts so that their designed performances are maintained throughout the mission. We have evaluated the mathematical models individually, which express the contaminant production, transport and deposition phenomena, with ground-based test data, however we did not assess the integrated models by flight data. The Hinode (Solar-B) is a highly sophisticated solar observational satellite equipped with three advanced solar telescopes: Solar Optical telescope (SOT), X-ray telescope (XRT) and EUV imaging spectrometer (EIS). Optical Telescope Assembly (OTA) of SOT has several sensitive components to molecular contaminants emitted from the CFRP, adhesives, etc. If the large volume of contaminants accumulate on the components, it is greatly concerned that increase of the solar absorptance leads to mission failure. For this reason, the outgassing sources were baked out up to 60 days, and monitored molecular deposition by QCM in thermal vacuum facilities. In order to assess the contamination impacts for the mission sequence, we made the OTA geometry model, conducted modeling outgassing rates of each source using the QCM data, and the numerical contamination analyses. It is expected that the OTA life time will be longer than three years in consideration of only the contamination effects. Then, The Hinode was launched on 22 September 2006 UT, and the SOT started solar observation on 25 October. The Hinode keeps on providing precious data smoothly for the scientists and engineers. We compared the OTA contamination analyses results with the OTA telemetry data, and discussed cause of the discrepancies.
- Abstract document