MIXS (Mercury Imaging X-ray Spectrometer) is an instrument in the remote sensing suite of the Mercury Planetary Orbiter (MPO), part of the Bepi-Colombo mission to Mercury. The optics for the MIXS instrument is funded by the European Space Agency. The development of the MIXS instrument is undertaken by an international consortium, led by the University of Leicester, UK. This is funded by the UK's Science & Technology Facilities Council. The instrument is intended to address scientific issues including:
-
the origin of Mercury,
-
the evolution of Mercury,
-
the nature of surface modifications on Mercury (e.g. cratering, volcanism),
There are two adjacent X-ray optics, each with different layouts, for the imaging telescope and an adjacent flux-collector (collimator).
Accurate thermal and geometrical mathematical models were needed to model the optics, taking into account the extreme thermal environment around Mercury. It was also necessary to understand the Mercurian orbit and the affects of Solar Albedo and Mercury shine on the optics
A number of analysis cases were identified and thermal predictions were produced for the various components. These predictions were used to evaluate the mechanical and optical performance of the optics.
This paper discusses the various issues associated with the modelling of the MIXS optics as well as the understanding of the Mercurian environment. The temperature predictions are shown for the cases analysed, from the one extreme of staring into space to the other of staring at the sun.