Design and Development of the VenSpec-H Instrument

• DOI: 10.5194/epsc2020-535
• Publication Date: 2020-10-08T10:35:58Z
• Authors: Jurgen Vanhamel; Ann-Carine Vandaele; Eddy Neefs; Séverine Robert; Lars Jacobs; Sophie Berkenbosch; Ian Thomas; Bram Beeckman; Wouter Moelans; Stefan Lesschaeve; Aaron Algoedt; Lieve De Vos; Matthew Vaughan
• Keywords: 13. Climate action; 621; 7. Clean energy

Introduction: VenSpec-H (Venus Spectrometer with High resolution), part of ESA’s EnVision M5 mission to Venus, is currently in Phase A (started January 2019) which the feasibility instrument studied. The successfully passed mid-term consolidation review (May 2020). selection by ESA planned beginning 2021. Scientific objectives: EnVision aims at investigation geo-logical activity on Venus and its relationship atmosphere, order understand how Earth could have evolved so differently. The VenSpec suite consists VenSpec-H two other instuments, VenSpec-M, an IR mapper, VenSpec-U, a UV spectrometer. overall scientific objective this search for temporal variations surface temperatures tropospheric concentrations gases indicative volcanic eruptions. Additionally, study surface-atmosphere interactions weathering mapping emissivity gas abundances also mission.The goal target different molecular species related volcanism changes Venus. measurement H2O HDO constituents Venus’ as well probing H2O, HDO, CO, OCS, SO2 30 – 40 km altitude range nightside above cloud top dayside. Several spectral windows are used monitor these 1 2.5 µm. works nadir viewing geometry. Instrument design: VenSpec-H spectrometer, hence, heart spectrometer section where incoming uniform light diffracted into components. This cooled down approximately -45 °C suppress much possible thermal background. achieved means large dedicated radiator. warm baseplate kept around 0 (by small radiator). mounted spacecraft deck using three kinematic feet.The diffracting element echelle grating. first rendered parallel parabolic mirror before it hits from grating focused optical system towards detector.The cold preceded warmer band section. It combination filter wheel butcher’s block horizontal filters (on entrance slit).The followed detector Integrated Dewar Detector Cooler Assembly (IDDCA). dewar window sits exit aperture Focal Plane Array (FPA) located bit further focal plane optics. FPA cryocooler.Preliminary analysis modelling has been performed.The design relies partly heritage NOMAD instrument, board Trace Gas Orbiter (TGO) satellite, ExoMars 2016 mission. Ongoing tests: Currently, thermo-mechanical prototyping work performed facilities BIRA-IASB, prove some critical systems. One most elements interconnection support structure. tests planned.In series tests, conductivity investigated types feet. Using fixed temperature one side, knowing heat injection ΔT can be determined.In second mounting mechanism onto connection side gliding pin tested. For this, prototype (including mass dummies elements) used, keeping -25°C, while base plate +20°C, retraction dilatation measured capacitive sensors.The results obtained during will presented conference. Acknowledgements:This Belgian Science Policy Office (BELSPO), financial contractual coordination Prodex Office.