FLORIS PFM acceptance test results

The Fluorescence Imaging Spectrometer (FLORIS) is the instrument of the Fluorescence Explorer Mission (FLEX) of the European Space Agency (ESA). Thales Alenia Space France is the satellite prime contractor while Leonardo S.p.a. is in charge of the FLORIS instrument development. One flight model is ordered by ESA, and the Proto-Flight Model (PFM) is currently undergoing its acceptance tests before being calibrated and finally delivered to the satellite. This paper will first recall the main design features of the FLORIS instrument, with the description of principle of the sub-systems such as the calibration unit, the polarization scrambler, the telescope, the high- and low-resolution spectrometers and the focal planes with their CCD detectors. Then the main steps of instrument integration and test plan will be described with a deeper focus on optical tests. The test results will be presented and compared to the success criteria and specifications. Both high and low resolution focal planes have been aligned and show very good geometrical and spectral performances. At the time when the article is written, the instrument will be fully integrated and will have undergone the environmental acceptance tests at Leonardo and Thales Alenia Space France premises. The remaining activities will be presented, in particular the calibration campaign and stray-light characterization to allow for in-orbit algorithm correction, which is a major performance objective for the instrument.