Vibration isolation system for cryocoolers on the XRISM

We discuss the design and performance of the vibration isolation system (VIS) used for the Resolve microcalorimeter on the X-Ray Imaging and Spectroscopy Mission (XRISM) spacecraft. Resolve makes high spectral resolution observations of celestial X-rays. XRISM was conceived as a recovery mission following the short-lived Hitomi mission. As such, the design of Resolve is similar to that of the soft X-ray spectrometer (SXS). A VIS was initially developed for the Hitomi SXS after discovering that vibrations from the cryocooler degraded the sensor’s performance. However, the VIS for Resolve was completely redesigned to include a hold-and-release mechanism to avoid damage to the compressor during launch or ground-based sine-vibe tests. The XRISM spacecraft was successfully launched in September 2023, confirming the functionality of the VIS while in orbit.