Development of mechanical cryocoolers for the cooling system of the Soft X-ray Spectrometer onboard Astro-H

► We have developed Engineering Models of the mechanical cryocoolers for ASTRO-H/SXS. ► Specific cooling power with margin for temperature and drive power was obtained. ► Double staged Stirling coolers can survive mechanical environment of ASTRO-H criteria. ► Continuous running for 5000 h had been achieved for lifetime test.