Ground based test verification of a nonlinear vibration isolation system for cryocoolers of the Soft X-ray Spectrometer (SXS) onboard ASTRO-H (Hitomi)

Inherently nonlinear vibration isolation systems offer compelling analytical performance advantages over their linear alternates. Verification testing followed by post-test correlation is essential to convincing otherwise conservative project management teams to adopt these technologies for their mission. This paper details a comprehensive test verification program developed and executed for a novel vibration isolation system developed for the Soft X-ray Spectrometer (SXS) onboard ASTRO-H (named Hitomi after launch). More specifically, the dual-stage / thermally conductive / nonlinear vibration isolation system developed for on-orbit amelioration of cryocooler-induced mechanical vibration, needed to undergo ground testing to demonstrate both on-orbit performance and launch induced response level rejection to protect sensitive payload temperature control components. The system, referred to as the VIS, realizes both small signal transmissibility at high frequency and small acceleration and displacement against vibration during launch and ground testing.