MICADO is a first light instrument for the Extremely Large Telescope (ELT), set to start operating later this decade. It will provide diffraction limited imaging, astrometry, high contrast imaging, and long slit spectroscopy at near-infrared wavelengths. During the initial phase operations, adaptive optics (AO) correction will be provided by its own natural guide star wavefront sensor. In its final configuration, that AO system will be retained and complemented by the laser guide star multi-conjugate adaptive optics module MORFEO (formerly known as MAORY). Among many other things, MICADO will study exoplanets, distant galaxies and stars, and investigate black holes, such as Sagittarius A* at the centre of the Milky Way. After their final design phase, most components of MICADO have moved on to the manufacturing and assembly phase. Here we summarize the final design of the instrument and provide an overview about its current manufacturing status and the timeline. Some lessons learned from the final design review process will be presented in order to help future instrumentation projects to cope with the challenges arising from the substantial differences between projects for 8-10m class telescopes (e.g. ESO’s VLT) and the next generation Extremely Large Telescopes (e.g. ESO’s ELT). Finally, MICADO's expected performance will be discussed in the context of the current landscape of astronomical observatories and instruments. For instance, MICADO will have similar sensitivity as the James Webb Space Telescope (JWST), but with six times the spatial resolution.
MICADO is the Multi-AO Imaging Camera for Deep Observations, a first light instrument for the Extremely Large Telescope (ELT). The instrument will be assisted by a Single-Conjugate Adaptive Optics (SCAO) system and the Multi conjugate Adaptive Optics RelaY (MAORY). MICADO can operate in the so-called stand-alone mode in the absence of MAORY with the SCAO correction alone. Here, we present the opto-mechanical final design of the Relay Optics (RO), the optical system relaying the ELT focal plane to an accessible position of MICADO for that SCAO-only stand-alone observing mode. The RO consists of an optical bench made of carbon fiber reinforced plastic (CFRP), an optical assembly made of three flat, motorized tip-tilt-piston mirrors and three powered mirrors of up to ~500 mm in diameter, the MICADO calibration assembly and a cover to protect all opto-mechanical components on top of the bench. A 9-point whiffletree support, combined with a thermal compensation system is implemented for the critical flat mirror (M6), while a more simple 3- point support is employed for the other two flat mirror M1 and M5. The powered mirrors (M2, M3, M4) comprising the relay's three mirror anastigmat (TMA) are supported by V-shape mounts. The static and the dynamic performance of the MICADO RO are investigated through a detailed Finite Element Analysis (FEA), whose results are combined with a Zernike basis representation of the surface deformations performed in Zemax for assessing the optical performance. The variation of the mirror position due to the operational temperature drift Delta T and other disturbances, is also considered in an end-to-end simulation. The required overall wavefront error of 100 nm rms is fulfilled with the current design proposal. Additionally, the results of a motorized tip-tilt-piston mirror mount prototype are presented as well..
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