The MTS, MIRI Telescope Simulator, is developed by INTA as the Spanish contribution of
MIRI (Mid InfraRed Instrument) on board JWST (James Web Space Telescope).
The MTS is considered as optical equipment which is part of Optical Ground Support
Equipment for the AIV/Calibration phase of the instrument at Rutherford Appleton
It is an optical simulator of the JWST Telescope, which will provide a diffractionlimited test
beam, including the obscuration and mask pattern, in all the MIRI FOV and in all defocusing
range. The MTS will have to stand an environment similar to the flight conditions (35K) but
using a smaller set-up, typically at lab scales.
The MTS will be used to verify MIRI instrument-level tests, based on checking the
implementation/realisation of the interfaces and performances, as well as the instrument
properties not subject to interface control such as overall transmission of various modes of
This paper includes a functional description and a summary of the development status.