Power and Synchronization Unit for Cameras in Space Applications

This paper discusses the Power Units developed to supply the cameras used for the PLATO (Planetary Transits and Oscillations of Stars) mission, which aims to find and characterize a large number of extrasolar planetary systems, focusing on the properties of terrestrial planets in the habitable zone around bright Sun-like stars. This mission will search for the answers to the scientific questions [1]: –How do planets and planetary systems form and evolve? –Is our solar system special or are there other systems like ours? –Are there potentially habitable planets? The PLATO science objectives are addressed by using long uninterrupted high precision photometric monitoring of large samples of stars. What distinguishes the PLATO payload from other spatial instruments is the use of several identical cameras, each participating to the pupil and the field of view of a virtual single instrument. This particular concept leads to the possibility of reaching a very high field of view. The prime data product will be a large sample of high precision stellar light curves in the visible, obtained over time intervals of a few months up to several years. The Payload houses 24 Normal cameras and 2 Fast cameras observing extremely bright stars. In order to supply the associated Camera Front End Electronic (FEE) the Ancillary Electronic Unit (AEU) has been developed, consisting of 2xN-AEU each one interfacing 12 Normal Cameras, and one F-AEU (which interfaces 2 Fast cameras). Each N-AEU consists of twelve independent power supplies (PSUs) and one Internal Supply Module (ISM) used to supply the Command Control Module (N-CCM). The F-AEU follows the same approach; thus, it hosts two PSUs feeding the F-Cameras and one ISM for the F-CCM. Moreover, this unit is in charge of generating synchronism for the F-FEE cameras, N- AEU units and Service Module (SVM) for Camera's heaters control.