An innovative concept for the AsteroidFinder/SSB focal plane assembly

This paper gives a summary on the system concept and design of the focal plane assembly of AsteroidFinder/SSB, a small satellite mission which is currently under development at the German Aerospace Center (DLR). An athermal design concept has been developed in accordance to the requirements of the instrument and spacecraft. Key aspects leading to this approach have been a trade-off study of the mechanical telescope interface, the definition of electrical and thermal interfaces and a material selection which minimizes thermally induced stresses. As a novelty, the structure will be manufactured from a machinable AlN–BN composite ceramic. To enable rapid design iterations and development, an integrated modeling approach has been used to conduct a thermo-mechanical analysis of the proposed concept in order to proof its feasibility. The steady-state temperature distribution for various load cases and the resulting stress and strain within the assembly have both been computed using a finite element simulation.

► The EMCCD detector array and proximity electronics will run at temperatures <−80 °C.
► The FPA structure will be manufactured from a machinable AlN–BN composite ceramic.
► A kinematic mount (three spheres in grooves) will be the interface to the telescope.
► A finite element model has been used for a thermo-mechanical analysis of the concept.
► An integrated modeling approach has enabled rapid development and assessment.