Takao Nakagawa

As a key technology in future earth observation and astronomical missions, a large-scale lightweight mirror constructed of silicon carbide-based material has been studied at JAXA. Silicon carbide was selected as the most promising candidate due to excellent characteristics of high specific stiffness and low CTE. One of the most important technical issues for large-scale ceramic components is quality stability (viz. differing in material property depending on part and processing) that might influence thermal and/or structural reliability due to unforeseen deformation and breakage. In this study, a propositional approach for the quality assurance technique of a practical flight mirror was examined, in which coupon samples extracted from various parts of the surrounding area of a newly manufactured φ800mm mirror were put to evaluation for estimating basic physical characteristics and homogeneity.

The 20K-class Double-staged Stirling cooler is a key cryogenic technology for cooling the optical detectors and telescopes of the highly-sophisticated astronomy satellite missions proposed by JAXA, for instance, the x-ray astronomy mission Astro-H(2013) and the cryogenic infrared telescope mission SPICA(2018). Therefore, it is required that the advanced double-staged Stirling cooler with improvement of mechanical reliability and cooling performance will be developed, based on the existing one onboard the first Japanese infrared astronomy mission Akari(2006) with cooling power of 200mW at 20K (90W power input). This paper describes about development status of the advanced double-staged Stirling cooler with cooling performance and long lifetime test.

The 20K-class Double-staged Stirling cooler is a key cryogenic technology for cooling the optical detectors and telescopes of the highly-sophisticated astronomy satellite missions proposed by JAXA, for instance, the x-ray astronomy mission Astro-H(2013) and the cryogenic infrared telescope mission SPICA(2018). Therefore, it is required that the advanced double-staged Stirling cooler with improvement of mechanical reliability and cooling performance will be developed, based on the existing one onboard the first Japanese infrared astronomy mission Akari(2006) with cooling power of 200mW at 20K (90W power input). This paper describes about development status of the advanced double-staged Stirling cooler with cooling performance and long lifetime test.