Paper 14145-120
Paper 14145-120
Development of a cryogenic test facility for Ariel’s primary mirror
5 July 2026 • 17:30 - 19:00 CEST | Room B4-M3
Abstract
The INAF Astronomical Observatory of Palermo has adapted the XACT facility to perform cryogenic testing of the 1-meter primary mirror for ESA’s Ariel mission, which operates at about 55 K. Thermoelastic effects at this temperature require a cryogenic interferometric campaign to recover the WFE and evaluate optical behavior in a representative environment. The facility includes a 2 m × 2 m vacuum chamber with a 1.4 m entrance hatch, a closed-loop helium cryocooler reaching 30 K, and an optical setup based on a 4D interferometer, a hexapod, and a vacuum optical window. The mirror is supported by an isostatic multi-DoF fork mount, with cooling provided through copper plates, heat shields, and thermal straps linked by an aluminum structure. Simulations show thermal gradients below 5 K and mirror temperatures below the required 90 K. The paper presents the setup, test activities, preliminary interferometric results, and related critical issues.
Presenter
INAF - Osservatorio Astronomico di Palermo "Giuseppe Salvatore Vaiana", Palermo (Italy)
Fabio D’Anca is a technologist at INAF Osservatorio Astronomico di Palermo, where he leads activities in cryogenic optical testing of space telescope mirrors and in the opto-mechanical qualification of space hardware. His work focuses on the development of a cryogenic facility for large-aperture optics and the dynamic characterization of ultra-thin optical filters and membranes. He has experience in vibration testing, precision metrology, vacuum systems, and single-point diamond turning processes for advanced optical manufacturing. He collaborates with ASI, ESA and NASA on technology development for missions such as Athena, Ariel and MUSE.