Space-borne survey instrument operations: lessons learned and new concepts for the Euclid NISP instrument

Euclid is the future ESA mission, mainly devoted to Cosmology. Like WMAP and Planck, it is a survey mission, to be launched in 2019 and injected in orbit far away from the Earth, for a nominal lifetime of 7 years. Euclid has two instruments on-board, the Visible Imager (VIS) and the Near- Infrared Spectro-Photometer (NISP). The NISP instrument includes cryogenic mechanisms, active thermal control, high-performance Data Processing Unit and requires periodic in-flight calibrations and instrument parameters monitoring. To fully exploit the capability of the NISP, a careful control of systematic effects is required. From previous experiments, we have built the concept of an integrated instrument development and verification approach, where the scientific, instrument and ground-segment expertise have strong interactions from the early phases of the project. In particular, we discuss the strong integration of test and calibration activities with the Ground Segment, starting from early pre-launch verification activities. We want to report here the expertise acquired by the Euclid team in previous missions, only citing the literature for detailed reference, and indicate how it is applied in the Euclid mission framework.