Engineering

VenSpec-H

2031: Spectrometer onboard of ESA’s EnVision mission to Venus. It aims at mapping the atmosphere near the surface and above the cloud deck.

VenSpec-H (Venus Spectrometer with High resolution) is part of ESA’s EnVision mission to Venus (launch foreseen in 2031). VenSpec-H is one of three in a spectrometer suite. The aim of VenSpec-H is to perform night side mapping of the near surface atmosphere and dayside mapping of the atmosphere above the cloud deck. VenSpec-H will measure gases related to volcanism and surface changes on Venus.

The Engineering department of BIRA-IASB contributed to the design work, document writing, and to performing preliminary mechanical and electrical concept tests.

VenSpec-H is a spectrometer. The heart of the instrument therefore consists of a spectrometer section where the incoming uniform light is diffracted into its spectral components. This section is cooled to approximately -45 °C in order to suppress as much as possible the thermal background. The diffracting element in VenSpec-H is an echelle grating. The incoming light is first rendered parallel on a parabolic mirror before it hits the grating. The parallel light diffracted from the grating is focused by a dedicated optical system towards the detector.

Blockschematic overview of the VenSpec-H instrument

The entrance of the spectrometer section is the spectrometer slit, the image of which is projected on the detector. The output of the spectrometer section is an opening interfacing to the detector assembly. The cold spectrometer section is preceded by a warmer band selection section. It is a combination of a filter wheel and a butcher’s block of two horizontal filters (on top of the spectrometer slit).

The spectrometer section is followed by the detector section. The detector is an Integrated Dewar Detector Cooler Assembly (IDDCA). The dewar window sits in the exit aperture of the spectrometer section. The Focal Plane Array (FPA) is located a bit further in the focal plane of the spectrometer exit optics. The FPA is cooled by means of a cryocooler.

 

Blockschematic overview of the VenSpec-H instrument

The VenSpec-H instrument breadboard installed for vibration testing (Bern, 2024).

 

Read more:

 

Publications:

  • E. Neefs, A.C. Vandaele, R. De Cock, J. Erwin, S. Robert, I.R. Thomas, S. Berkenbosch, L. Jacobs, P. Bogaert, B. Beeckman, A. Brassine, N. Messios, E. De Donder, D. Bolsée, N. Pereira, P. Tackley, T. Gerya, S. Kögl, P. Kögl, H.-P. Gröbelbauer, F. Wirz, G. Székely, N. Eaton, E. Roibás-Millán, I. Torralbo, H. Rubio-Arnaldo, J.M. Alvarez, D. Navajas Ortega, L. De Vos, R. Sørensen, W. Moelans, A. Algoedt, M. Blau, D. Stam, E. Renotte, P. Klinkenberg, B. Borguet, S. Thomas, M. Vervaeke, H. Thienpont, J.M. Castro, J. Jimenez. VenSpec-H spectrometer on the ESA EnVision mission: Design, modeling, analysis. Acta Astronomica, Volume 226, January 2025: https://doi.org/10.1016/j.actaastro.2024.10.018

  • Helbert, J.; Vandaele, A.C.; Marcq, E.; Robert, S.; Ryan, C.; Guignan, G.; Rosas-Ortiz, Y.; Neefs, E.; Thomas, I.R.; Arnold, G.; Peter, G.; Widemann, T.; Lara, L. (2019), “The VenSpec suite on the ESA EnVision mission to Venus”, (Strojnik, M., Ed.), Proceedings of SPIE 11128: Infrared Remote Sensing and Instrumentation XXVII, 9 September 2019, San Diego, USA, Vol. 11128, A1112804, DOI: 10.1117/12.2529248

  • Robert, S.; Vandaele, A.C.; Neefs, E.; Jacobs, L.; Berkenbosch, S.; Thomas, I.R.; Helbert, J.; Marcq, E.; Wilson, C.; Bézard, B.; Widemann, T.; Ghail, R. (2019), “VenSpec-H, infrared spectrometer onboard EnVision to study Venus’ volcanism”, EPSC-DPS Joint Meeting 2019, 15-20 September 2019, Geneva, Switzerland, Vol. 13, EPSC-DPS2019-1670-1