27 research outputs found
Design of the VenSpec-H instrument on ESA¿s EnVision mission: development of critical elements, highlighting the FFCP, and grating
No full textDe Cock, Roderick et al.-- Full list of authors: De Cock, Roderick; Robert, Séverine; Neefs, Eddy; Erwin, Justin; Vervaeke, Michael; Thienpont, Hugo; Renotte, Etienne; Klinkenberg, Philippe; Borguet, Benoit; Thomas, Solal; Moelans, Wouter; Algoedt, Aaron; De Vos, Lieve; Sørensen, Ramatha; Blau, Moshe; Vandaele, Ann Carine; Thomas, Ian R.; Berkenbosch, Sophie; Jacobs, Lars; Bogaert, Pieter; Beeckman, Bram; Brassine, Ansje; Messios, Neophytos; De Donder, Erwin; Bolsée, David; Pereira, Nuno; Ristic, Bojan; Tackley, Paul J.; Gerya, Taras; Kögl, Stefan; Kögl, Paola; Gröbelbauer, Hans-Peter; Wirz, Florian; Székely, Gerhard Stefan; Eaton, Nick; Roibás-Millán, Elena; Torralbo, Ignacio; Rubio-Arnaldo, Higinio; Álvarez, José Miguel; Navajas Ortega, Daniel; Stam, Daphne; Castro-Marin, Jose M.; Jiménez Ortega, Jaime; Lara, Luisa; Helbert, Jörn; Alemanno, Giulia; Marcq, Emmanuel.-- Part of the Proceedings of SPIE- - The International Society for Optical Engineering Volume 13144 article number 131440E Infrared Remote Sensing and Instrumentation XXXII 2024 San Diego18 August 2024 through 20 August 2024 Code 204177The VenSpec-H development is under the responsibility of a Belgian Instrument Lead team (BIRA-IASB, Brussels). Contributions are provided by research institutes or industrial companies in Europe:
• in Switzerland: ETHZ, KOEGL Space, FHNW, HSLU, and Space Acoustics;
• in Spain: IDR-UPM and IAA-CSIC;
• in The Netherlands: Leiden Observatory;
• in Germany: DLR and AIM;
• in Belgium: OIP, AMOS and B-PHOT VUB.
Support was also received from the EnVision (study and) project team and the PRODEX team at ESTEC.
The optical design work and the development of the FFCP, the grating and the TWU are made possible
thanks to funding by the Belgian Science Policy Office (BELSPO). The development of the FWM is made possible thanks to funding by the Swiss Space office (SSO). The European Space Agency (ESA) was in charge for
the purchase of the IDCA.
VenSpec-H work not specifically mentioned in this paper (e;g., mechanical and electrical development), falls
under funding from the Belgian Science Policy Office (BELSPO) (Prodex Experiment Agreement C4000128137),
the Swiss Space office (SSO) (Prodex Experiment Agreements 4000138690, 4000138246 and 4000138247) and
the Spanish Agencia Estatal de Investigaci´on (grants PID2021-126365NB-C21 and PID2021-126365NA-C22).
Funding from Belgium and Spain was financially and contractually coordinated by the ESA Prodex Office.
EM acknowledges support from CNES and ESA for all EnVision-related activities
Design of the VenSpec-H instrument on ESA's EnVision mission: Development of critical elements, highlighting the wavefront corrector and grating
No full textDe Cock, Roderick et al.-- Full list of authors: De Cock, Roderick; Robert, Séverine; Neefs, Eddy; Erwin, Justin; Vervaeke, Michael; Thienpont, Hugo; Renotte, Etienne; Klinkenberg, Philippe; Borguet, Benoit; Thomas, Solal; Moelans, Wouter; Algoedt, Aaron; De Vos, Lieve; Sørensen, Ramatha; Blau, Moshe; Carine Vandaele, Ann; Thomas, Ian R.; Berkenbosch, Sophie; Jacobs, Lars; Bogaert, Pieter; Beeckman, Bram; Brassine, Ansje; Messios, Neophytos; De Donder, Erwin; Bolsée, David; Pereira, Nuno; Ristic, Bojan; Tackley, Paul J.; Gerya, Taras; Kögl, Stefan; Kögl, Paola; Gröbelbauer, Hans-Peter; Wirz, Florian; Székely, Gerhard Stefan; Eaton, Nick; Roibás-Millán, Elena; Torralbo, Ignacio; Rubio-Arnaldo, Higinio; Álvarez, José Miguel; Ortega, Daniel Navajas; Stam, Daphne; Castro-Marin, Jose M.; Ortega, Jaime Jiménez; Lara, Luisa; Helbert, Jörn; Alemanno, Giulia; Marcq, Emmanuel.EnVision is the European Space Agency’s upcoming mission to Venus with a launch scheduled in 2031. One of the payloads on board is the Venus Spectrometers (VenSpec) suite, containing three spectrometer channels, one of which is Venus Spectrometer with high resolution (VenSpec-H). VenSpec-H performs absorption measurements in the atmosphere of Venus in four near-infrared spectral bands. VenSpec-H is developed under Belgian management and builds on heritage from instruments on Venus Express and Trace Gas Orbiter. The operating wavelength range (1.15 to 2.5μm) imposes stringent temperature requirements on the instrument to make nightside measurements below the Venus clouds possible. Most importantly, the spectrometer’s optical components are held in a separate cold section inside the instrument, cooled down to −45°C, to remove the thermal background from the signal. Some passive optical elements in the cold spectrometer had low technological readiness at the start of the project. One of them is a wavefront corrector: the freeform corrector plate, used to compensate for aberrations introduced in the system by a parabolic mirror. This device is developed by the Brussels Photonics lab of Vrije Universiteit Brussel using a supply chain with shape-adaptive corrective polishing and dedicated metrology. Another is the echelle grating, used to disperse the incoming light into its spectral components, which is built by Advanced Mechanical and Optical Systems. We highlight the manufacturing and metrology processes of both devices. Besides that, some mechanisms, placed in the warmer part of the instrument, had to be developed: a turn window unit to protect the interior of the instrument during the aerobraking phase of the mission, a filter wheel mechanism to select the spectral bands of interest, and an integrated detector cooler assembly to register the spectra © The AuthorsThe VenSpec-H development is under the responsibility of a Belgian Instrument Lead team (BIRA-IASB, Brussels). Contributions are provided by research institutes or industrial companies in Europe:
• in Switzerland: ETHZ, KOEGL Space, FHNW, HSLU, and Space Acoustics;
• in Spain: IDR-UPM and IAA-CSIC;
• in the Netherlands: Leiden Observatory;
• in Germany: DLR and AIM;
• in Belgium: OIP, AMOS, and B-PHOT VUB.
Support was also received from the EnVision (study and) project team and the PRODEX team at ESTEC.
The optical design work and the development of the FFCP, the grating, and the TWU are made possible, thanks to the funding of the Belgian Science Policy Office (BELSPO). The development of the FWM is made possible thanks to the funding of the Swiss Space Office (SSO). The ESA was in charge of the purchase of the IDCA. VenSpec-H work, not specifically mentioned in this paper (e.g., mechanical and electrical development), falls under funding from the Belgian Science Policy Office (BELSPO) (Prodex Experiment Agreement No. 4000128137), the Swiss Space Office (SSO) (Prodex Experiment Agreement Nos. 4000138690, 4000138246, and 4000138247), and the Spanish Agencia Estatal de Investigación (Grant Nos. PID2021-126365NB-C21 and PID2021-126365NA-C22). Funding from Belgium and Spain was financially and contractually coordinated by the ESA Prodex Office.
E.M. acknowledges support from CNES and ESA for all EnVision-related activities.
This paper was produced for SPIE optics and photonics 2024.25,26Peer reviewe
Terrestrial Planet Optical Phase Curves. I. Direct Measurements of the Earth
No full textNASA's EPOXI mission used the Deep Impact spacecraft to observe the disk-integrated Earth as an analog to terrestial exoplanets' appearance. The mission took five 24 hr observations in 2008-2009 at various phase angles (57. 7-86. 4) and ranges (0.11-0.34 au), of which three equatorial (E1, E4, E5) and two polar (P1, North and P2, South). The visible data taken by the HRIV instrument ranges from 0.3 to 1.0 μm, taken trough seven spectral filters that have spectral widths of about 100 nm, and which are centered about 100 nm apart, from 350 to 950 nm. The disk-integrated, 24 hr averaged signal is used in a phase angle analysis. A Lambertian-reflecting, spherical planet model is used to estimate geometric albedo for every observation and wavelength. The geometric albedos range from 0.143 (E1, 950 nm) to 0.353 (P2, 350 nm) and show wavelength dependence. The equatorial observations have similar values, while the polar observations have higher values due to the ice in view. Therefore, equatorial observations can be predicted for other phase angles, but (Earth-like) polar views (with ice) would be underestimated.Astrodynamics & Space Mission
Electrical Integration of the VenSpec Spectrometer Consortium: An Architecture Trade-off
No full textFitzner, Alexander et al.-- Full list of authors: Fitzner, Alexander; Hafemeister, Lisa; Del Togno, Simone; Lötzke, Horst-Georg; Wendler, Belinda; Wolff, Friederike; Helbert, Jörn; Gutiérrez-Marqués, Pablo; Nathues, Andreas; Perplies, Henry; Loose, Alexander; Fischer, Henning; Marlur, Vrushabh; Hall, Ian; Meller, Reinhard; Castro, Jose M.; Jiménez Ortega, Jaime; Lara, Luisa M.; Alvarez, Fernando; Nogales, Álvaro Mazuecos; Fiethe, Björn; Gómez, Andrès.; Buchhorn, Dennis; Neefs, Eddy; De Cock, Roderick; Erwin, Justin; Robert, Séverine; Vandaele, Ann-Carine; Berkenbosch, Sophie; Hagelschuer, Till; Peter, Gisbert; Pertenais, Martin; Lustrement, Benjamin; Hassen-Khodja, Rafik; Vivat, Francis; Bertran, Sandrine; Marcq, Emmanuel; Parro, Vanderlei Cunha; França, Rodrigo de Marca.-- Part of the Proceedings of SPIE- - The International Society for Optical Engineering Volume 13144 Article number 131440D Infrared Remote Sensing and Instrumentation XXXII 2024 San Diego 18 August 2024 through 20 August 2024 Code 204177For ESA's EnVision Mission to Venus, a consortium of three spectrometers from across Europe has been formed to collaborate not only on the management and science aspects, but also on the technical implementation. One important technical goal of the VenSpec suite is to implement a clean, simple and robust interface to the spacecraft and to provide an abstraction layer between the channels and the spacecraft. This is achieved by implementing the Central Control Unit (CCU), which provides a harmonized power and data interface to the spacecraft and allows the channels to design for a simple tailored internal interface to the CCU. The CCU consists of two electrical subsystems, the Data Handling Unit (CCU DHU), developed by the Max Planck Institute for Solar System Research (MPS) in Göttingen and the Institute of Computer and Network Engineering (IDA) in Braunschweig and the Power Supply Unit (CCU PSU), developed by the Instituto de Astrofísica de Andalucía (IAA-CSIC) in Granada, the system responsibility being at the DLR Institute of Planetary Research (DLR-PF) in Berlin. Within this framework, an extended electrical architecture trade-off was performed in 2023 to optimize the system, guaranteeing the requested functionality and complying to requirements from all sides. As a result of the trade-off. a single power and data interface were found to be the most suitable and robust solution considering performance, reliability, Fault Detection Isolation and Recovery (FDIR) and Electromagnetic Compatibility (EMC) considerations as well as the complexity of the associated verification campaign. This paper demonstrates the options that were suggested by the different parties and justifies the final architecture, which has been chosen to achieve the best solution for the VenSpec suite. © 2024 SPIEThe CCU team thanks the ESA Study team, especially Pierre-Elie Crouzet for their support in discussing different
approaches.
The DHU team acknowledges the financial support of the German Space Agency (DLR).
The IAA team acknowledges financial support from project PID2021-126365NB-C21 (MCI/AEI/FEDER, UE)
'Visions of an unseen world': the production and consumption of English ghost stories, c.1660-1800
No full textThis thesis traces the cultural significance of ghost beliefs in English society from c.1660 to c.1800. It is an attempt to partially re-enchant these years and to nuance historical characterisation of eighteenth-century England as an enlightened, secularising and ‘anti-superstitious’ nation. Moreover, I aim to restore ghost beliefs to historical legitimacy and my central argument is that they played a crucial role in shaping the specific social, political, economic and religious contours of eighteenth-century life. Ghosts have been largely exorcised from existing accounts of this period and so this research represents a fresh contribution to historical understandings of the long eighteenth century and to historiographies of the supernatural more generally.
The following chapters describe how ghost beliefs blended with the religious cultures of Anglicanism and Methodism by reinforcing orthodox theological teachings. The idea that dead souls could return to earth also complemented clerical initiatives to reform lay spirituality and to temper the extremes of rational religion. I chart how ghost beliefs fared in the face of new enlightenment philosophies, and how they informed discourse of politeness, individuality and interiority. This is accompanied by explorations of the relevance of ghost beliefs in everyday life. I describe the places and spaces in which ghost stories were told, the people who narrated them and those who listened. This ‘thick description’ emphasises how the spread of ghost stories was encouraged by contemporary labour relations, by the expansion of British imperial and trading interests overseas, and by patterns of sociability that were intrinsically linked to the realities of eighteenth-century life.
I have harnessed insights from socio-linguistics and the sociology of literature to theorise the relationship between ghost stories and ghost beliefs. I have examined the production, circulation and consumption of ghost stories, as well as their form and content, to explain how these texts reflected and shaped the opinions of a variety of readers. In so doing, this thesis suggests an important relationship between literary forms and historical change
The VenSpec-H instrument onboard EnVision
No full textInternational audienceThe VenSpec-H instrument is part of the EnVision M5 mission payload, which has been selected by ESA in June 2021 for launch in 2031. EnVision is a medium-class mission [1] to determine the nature and current state of geological activity on Venus, and its relationship with the atmosphere, to understand how Venus and Earth could have evolved so differently. VenSpec-H will target different molecular species in nadir viewing geometry, as to better characterize the surface-atmosphere interaction. VenSpec-H is part of the VenSpec suite [2], including also an IR mapper and a UV spectrometer [3].The instrument is a nadir pointing, high-resolution infrared spectrometer that will perform observations between 1 and 2.5 microns. This instrument was original developed with direct heritage from NOMAD-LNO [4, 5] /ExoMars Trace Gas Orbiter. Due to the scientific requirements of the EnVision mission, a series of modifications have been introduced to address the spectral coverage and SNR of the instrument
The VenSpec-H instrument onboard EnVision
No full textInternational audienceThe VenSpec-H instrument is part of the EnVision M5 mission payload, which has been selected by ESA in June 2021 for launch in 2031. EnVision is a medium-class mission [1] to determine the nature and current state of geological activity on Venus, and its relationship with the atmosphere, to understand how Venus and Earth could have evolved so differently. VenSpec-H will target different molecular species in nadir viewing geometry, as to better characterize the surface-atmosphere interaction. VenSpec-H is part of the VenSpec suite [2], including also an IR mapper and a UV spectrometer [3].The instrument is a nadir pointing, high-resolution infrared spectrometer that will perform observations between 1 and 2.5 microns. This instrument was original developed with direct heritage from NOMAD-LNO [4, 5] /ExoMars Trace Gas Orbiter. Due to the scientific requirements of the EnVision mission, a series of modifications have been introduced to address the spectral coverage and SNR of the instrument
VenSpec-H spectrometer on the ESA EnVision mission: Instrument’s status
No full textInternational audienceVenSpec-H is part of the VenSpec suite [1], also including an IR mapper and a UV spectrometer [2]. The suite science objectives are to search for temporal variations in surface temperatures and tropospheric concentrations of volcanically emitted gases, indicative of volcanic eruptions; and to study surface-atmosphere interactions. Maintenance of the clouds requires a constant input of H2O and SO2. A large eruption would locally alter the composition by increasing abundances of H2O, SO2, and CO and perhaps decreasing the D/H ratio. Observations of changes in lower atmospheric SO2, CO, and H2O vapour levels, cloud level H2SO4 droplet concentration, and mesospheric SO2, are therefore required to link specific volcanic events with past and ongoing observations of the variable and dynamic mesosphere, to understand both the importance of volatiles in volcanic activity on Venus and their effect on cloud maintenance and dynamics. VenSpec-H’s main scientific objectives are (1) to better constrain the composition of the atmosphere both below and above the clouds to relate changes in the composition to changes on the surface or geological processes such as volcanism; (2) to investigate short and long-term trends in the composition to better grasp the climate evolution on Venus [3].VenSpec-H is designed to measure H2O, HDO, CO, OCS, and SO2 on both the night and day side to contribute to this investigation. VenSpec-H is a nadir-pointing, high-resolution (R~8000) infrared spectrometer that will perform observations in different spectral windows between 1 and 2.5 µm. Spectra in these bands will be recorded sequentially with the help of a filter wheel and will allow the sounding of different layers in the Venusian atmosphere: close to the surface (1.17 µm), 15-30 km (1.7 µm), 30-40 km (2.4 µm) and above the clouds (1.38 & 2.4 µm) [4]. Two additional polarization filters will be used during dayside observations to better characterize the clouds’ properties and mitigate the impact of polarization. A 3D drawing of the instrument and its electronic box is shown in Fig. 1.Figure 1: 3D drawings of the electronic box (left) and the optical bench (right), from Neefs et al., 2025 [4].Significant progress has been made recently on the technical side. The optical components (FFCP and grating) passed their TRL evaluation campaigns by proving performance under thermovacuum conditions. The filter wheel mechanism succeeded by completing a lifetime test (>1M movements) under thermovacuum tests, in addition to shock and vibration testing. The B1 breadboard was manufactured, which contained warm and cold baseplates with feet and flexures and aluminum boxes. Mass dummies for other components (filter wheel, detector, turn window unit, and optical components) were used to perform and shock and vibration test. Some of the engineering models of the Integrated detector and cooler assembly (IDCA) were delivered. Prototype electronics were built to control and readout the IDCA and performance tests were made. The development of critical elements are described in [5]. Mechanical design continues, as updates to all subsystems need to be integrated to ensure compatibility.The expected instrument performance and the ability to meet the science requirements are continuously investigated, for instance, by revisiting previous datasets [6] or by performing modelling exercises [7]. The planning of calibrations and operations is also ongoing work. Building a new instrument is a challenge that requires an incredible team and support. There are so many aspects to it and nothing can be left to chance. Luckily, VenSpec-H is in good hands. In this presentation we will highlight the most important achievements of the past year
Assessing near-surface radiance levels based on VIRTIS spectra to prepare VenSpec-H science
No full textInternational audienc
