Share Email Print
cover

Proceedings Paper • Open Access

Alignment procedure for the Gregorian telescope of the Metis coronagraph for the Solar Orbiter ESA mission
Author(s): Vania Da Deppo; Sergio Mottini; Giampiero Naletto; Fabio Frassetto; Paola Zuppella; Mewael G. Sertsu; Marco Romoli; Silvano Fineschi; Ester Antonucci; Gianalfredo Nicolini; Piergiorgio Nicolosi; Daniele Spadaro; Vincenzo Andretta; Marco Castronuovo; Marta Casti; Gerardo Capobianco; Giuseppe Massone; Roberto Susino; Federico Landini; Maurizio Pancrazzi; Chiara Casini; Luca Teriaca; Michela Uslenghi

Paper 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.

Paper Details

Date Published: 12 July 2019
PDF: 11 pages
Proc. SPIE 11180, International Conference on Space Optics — ICSO 2018, 1118076 (12 July 2019);
Show Author Affiliations
Vania Da Deppo, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Sergio Mottini, Thales Alenia Space (Italy)
Giampiero Naletto, Univ. degli Studi di Padova, CNR, INAF, CISAS (Italy)
Fabio Frassetto, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Paola Zuppella, CNR-Istituto di Fotonica e Nanotecnologie (Italy)
Mewael G. Sertsu, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (Germany)
Marco Romoli, Univ. degli Studi di Firenze (Italy)
Silvano Fineschi, INAF – Osservatorio Astrofisico di Torino (Italy)
Ester Antonucci, INAF – Osservatorio Astrofisico di Torino (Italy)
Gianalfredo Nicolini, INAF – Osservatorio Astrofisico di Torino (Italy)
Piergiorgio Nicolosi, Univ. degli Studi di Padova (Italy)
Daniele Spadaro, INAF – Osservatorio Astrofisico di Catania (Italy)
Vincenzo Andretta, INAF – Osservatorio Astronomico di Capodimonte (Italy)
Marco Castronuovo, Agenzia Spaziale Italiana (Italy)
Marta Casti, INAF – Osservatorio Astrofisico di Torino (Italy)
Gerardo Capobianco, INAF – Osservatorio Astrofisico di Torino (Italy)
Giuseppe Massone, INAF – Osservatorio Astrofisico di Torino (Italy)
Roberto Susino, INAF – Osservatorio Astrofisico di Torino (Italy)
Federico Landini, INAF – Osservatorio Astrofisico di Arcetri (Italy)
Maurizio Pancrazzi, Univ. degli Studi di Firenze (Italy)
Chiara Casini, Univ. degli Studi di Firenze (Italy)
Luca Teriaca, Max Planck Institute for Solar System Research (Germany)
Michela Uslenghi, INAF-IASF (Italy)


Published in SPIE Proceedings Vol. 11180:
International Conference on Space Optics — ICSO 2018
Zoran Sodnik; Nikos Karafolas; Bruno Cugny, Editor(s)

© SPIE. Terms of Use
Back to Top
PREMIUM CONTENT
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?
close_icon_gray