The ESTO IIP-07 task “Panchromatic Fourier Transform Spectrometer (PanFTS) for the Geostationary Coastal and Air Pollution Events (GEO-CAPE) Mission”, led by PI Stan Sander at JPL, has recently completed the one-year accelerated life testing on the optical path difference mechanism (OPDM). The primary function of the OPDM is to translate the moving mirror element of the Michelson interferometer. The two most important OPDM performance characteristics are to keep the moving mirror perpendicular to the optical beam by the OPDM’s piezo-actuated tip/tilt stage, and to smoothly translate the mirror with minimal jitter.

During the 12-month long accelerated life test, the OPDM was cycled more than 2.6 million times over its full range of travel (0 mm to 50 mm) in hard vacuum at -100° C. This set of test parameters and duration was to demonstrate an equivalence of 5 years of space operation. After the test, the ability of the tip/tilt stage to keep the mirror aligned remained unchanged, and the translation stability of the OPDM continued to be excellent and was well below the 1% design requirement.