Metis is a solar coronagraph mounted on-board the Solar Orbiter ESA spacecraft. Solar Orbiter is scheduled for launch in February 2020 and it is dedicated to study the solar and heliospheric physics from a privileged close and inclined orbit around the Sun. Perihelion passages with a minimum distance of 0.28 AU are foreseen. Metis features two channels to image the solar corona in two different spectral bands: in the HI Lyman at 121.6 nm, and in the polarized visible light band (580 - 640 nm). Metis is a solar coronagraph adopting an "inverted occulted" configuration. The inverted external occulter (IEO) is a circular aperture followed by a spherical mirror which back rejects the disk light. The reflected disk light exits the instrument through the IEO aperture itself, while the passing coronal light is collected by the Metis telescope. Common to both channels, the Gregorian on-axis telescope is centrally occulted and both the primary and the secondary mirror have annular shape. Classic alignment methods adopted for on-axis telescope cannot be used, since the on-axis field is not available. A novel and ad hoc alignment set-up has been developed for the telescope alignment. An auxiliary visible optical ground support equipment source has been conceived for the telescope alignment. It is made up by four collimated beams inclined and dimensioned to illuminate different sections of the annular primary mirror without being vignetted by other optical or mechanical elements of the instrument.

Alignment procedure for the Gregorian telescope of the Metis coronagraph for the Solar Orbiter ESA mission / Da Deppo, Vania and Mottini, Sergio and Naletto, Giampiero and Frassetto, Fabio and Zuppella, Paola and Sertsu, Mewael G. and Romoli, Marco and Fineschi, Silvano and Antonucci, Ester and Nicolini, Gianalfredo and Nicolosi, Piergiorgio and Spadaro, Daniele and Andretta, Vincenzo and Castronuovo, Marco and Casti, Marta and Capobianco, Gerardo and Massone, Giuseppe and Susino, Roberto and Landini, Federico and Pancrazzi, Maurizio and Casini, Chiara and Teriaca, Luca and Uslenghi, Michela. - STAMPA. - 11180:(2019), pp. 76-86. (Intervento presentato al convegno International Conference on Space Optics - ICSO 2018, 2018, Chania, Greece) [10.1117/12.2536177].

Alignment procedure for the Gregorian telescope of the Metis coronagraph for the Solar Orbiter ESA mission

Romoli, Marco;Pancrazzi, Maurizio;Casini, Chiara;
2019

Abstract

Metis is a solar coronagraph mounted on-board the Solar Orbiter ESA spacecraft. Solar Orbiter is scheduled for launch in February 2020 and it is dedicated to study the solar and heliospheric physics from a privileged close and inclined orbit around the Sun. Perihelion passages with a minimum distance of 0.28 AU are foreseen. Metis features two channels to image the solar corona in two different spectral bands: in the HI Lyman at 121.6 nm, and in the polarized visible light band (580 - 640 nm). Metis is a solar coronagraph adopting an "inverted occulted" configuration. The inverted external occulter (IEO) is a circular aperture followed by a spherical mirror which back rejects the disk light. The reflected disk light exits the instrument through the IEO aperture itself, while the passing coronal light is collected by the Metis telescope. Common to both channels, the Gregorian on-axis telescope is centrally occulted and both the primary and the secondary mirror have annular shape. Classic alignment methods adopted for on-axis telescope cannot be used, since the on-axis field is not available. A novel and ad hoc alignment set-up has been developed for the telescope alignment. An auxiliary visible optical ground support equipment source has been conceived for the telescope alignment. It is made up by four collimated beams inclined and dimensioned to illuminate different sections of the annular primary mirror without being vignetted by other optical or mechanical elements of the instrument.
2019
procspie
International Conference on Space Optics - ICSO 2018, 2018, Chania, Greece
Da Deppo, Vania and Mottini, Sergio and Naletto, Giampiero and Frassetto, Fabio and Zuppella, Paola and Sertsu, Mewael G. and Romoli, Marco and Fine...espandi
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1174847
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