Space Telescope Lens Tests
A technical paper published in 2012 describes how Philtec’s high precision sensors were successfully used at 150°K to verify the distortion of lens holders to be <1 micron, well within the project requirements.
‘Test Results of High-Precision Large Cryogenic Lens Holders’, 2012, Proceedings of the SPIE Publication “Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II”.
The complete description of Philtec sensor installation and calibrations at cryogenic temperatures are found in ‘Section 4 Metrology’.
This work was conducted to verify the accuracy of the Euclid Space Telescope Lenses. Euclid is a space telescope currently under development by the European Space Agency and the Euclid Consortium. Launch date scheduled for 2022.