MIOSAT

The implementation of this mission aims at developing and qualify in orbit new technological products, among which electro-optical systems making up the core of the payload. The technological target aims at better understanding the complex physical systems of the Earth through the use of high resolution Spectroscopy capable of providing, in addition to the geometric image, also the spectral features of the observed scenario.

The Prime contractor to ASI is Rheinmetall Italia (RHI).  Spacesys has been involved in two activities under subcontract to RHI:

- a revision of the platform documentation , concerning both the RHI-issued  requirements and the specifications proposed by the Suppliers;

- a parallel study of a high resolution telescope looking at the feasibility of its realization using COTS devices. This was intended to be a backup solution in case of problems with the baseline Supplier;

 Spacesys backup solution for the High Resolution Telescope

MIOSAT flies at 500 km altitude and the baseline telescope has a pupil diameter of 0.25 m, and aims at a swath of 8 km implying an F# around 7 and a CCD with 2000 pixels of 13 microns each in the focal plane. Looking for a backup solution we performed a full survey of COTS linear arrays and even complete FPA assemblies, identifying several candidate alternatives. Starting from these the optical system was reconsidered achieving good results.

Ray tracing and aberrations computed for the optical system.The latter is a modified Cassegrain with correcting lenses on the aperture, and a field flattener in front of the FPA.

The telescope study did consider the mechanical aspects which have a great impact on the accuracy and stability, thus on the optical image quality. The testing problems were discussed too, concerning both the ground and in-orbit testing, and cost-effective proposals were put forward.

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