ESA’s Science Program Committee (SPC) has approved the start of development of the EnVision mission, dedicated to the study of Venus as part of the Cosmic Vision program’s M5 mission.
Now that the study phase is considered complete, ESA is committed to implementing the mission. After the selection of a European manufacturer in autumn 2024, the design of the probe and its scientific payload will be finalized, followed by their development.
EnVision is scheduled to be launched by an Ariane 62 rocket from Kourou in 2031.
A terrestrial planet. - The sun rises above the thick cloud cover, reflected in the solar panels of the EnVision mission. The instrument suite will provide space coverage of Venus during the nominal phase of the mission, from a low polar orbit with a period of around 1h40.
© ESA
Setting course for our largest neighbor
The exploration of Venus offers a unique opportunity to answer fundamental questions about the evolution of Earth-like planets and long-term habitability in a planetary system.
Many scientific questions remain in our understanding of the causes of the divergent evolution of Venus and Earth throughout the history of the Solar System. Studying and better understanding how the interior, surface and atmosphere of Earth and Venus evolved into two such different planets today, is essential to constrain what makes a terrestrial-mass planet habitable over the long term. And this point is particularly topical at a time when thousands of terrestrial exoplanets are expected to be discovered, at various stages of their evolution.
Ces terrains complexes ont été révélés par les images prises par la mission Magellan de la NASA au début des années 1990.
EnVision prendra des images radar environ dix fois plus détaillées d’une grande partie de ces terrains afin de répondre à des questions sur l’évolution à long terme de l’intérieur, la surface ou la composition de l’atmosphère.
From the core to the upper atmosphere
Designed in partnership with NASA, which will supply the main instrument (the Jet Propulsion Laboratory’s VenSAR synthetic aperture radar), EnVision will reveal how volcanism, tectonics and the planet’s geological history in general have shaped the surface and atmosphere of Venus as we know it today.
Thanks to its very low orbit, comparable to that of the ISS around the Earth, the mission will also explore the planet’s interior, gathering gravimetric data on the structure and characteristics of the core, mantle and lithosphere.
![<multi>[fr]Une mission pour l'étude simultanée de la surface, l'intérieur et l'atmosphère de anotre voisine.[en]A mission to simultaneously study our neighbor's surface, interior and atmosphere.</multi>](IMG/jpg/envision2.jpg)
Trois spectromètres différents, VenSpec-M, VenSpec-H, et VenSpec-U, étudieront la composition et la structure de la surface et de l’atmosphère. Les équipes de l’Observatoire de Paris - PSL joueront un rôle essentiel dans la préparation de ces instruments.
Enfin, une expérience de radio science étudiera la structure interne de la planète et les propriétés de l’atmosphère
A second radar designed by the Italian space agency, SRS, will send echoes beneath the surface to characterize the various geological interfaces.
Finally, a suite of three spectrometers in the ultraviolet and near-infrared ranges will precisely measure the interactions between the interior, surface and atmosphere, and help us understand how these geophysical envelopes interact with each other.
France and Observatoire de Paris-PSL strongly committed
CNES is heavily involved in this mission, not only as a contributor to ESA’s mandatory scientific program budget, but also through the supply of its scientific payload.
France’s contribution to the on-board instruments is very significant :
- The Laboratoire de Planétologie de Nantes Université is responsible for the radio-science experiment, in which the Institut de mécanique céleste et de calcul des éphémérides (Observatoire de Paris - PSL) is participating ;
- The VenSpec-U ultraviolet imaging spectrometer will be built by a consortium of French space laboratories : LATMOS, LESIA and IRAP ;
- The optical part of the VenSpec-M infrared multi-spectral imager will be designed, developed and tested at LESIA, with technical support from CNES.
Thomas Widemann, astrophysicist at Observatoire de Paris-PSL, coordinated the EnVision mission science team during the proposal, selection and adoption phases between 2016 and 2024.
Observatory teams are also playing a key role in preparing the onboard instruments for Venus, as well as designing the hardware and software tools needed to test system performance prior to integration.
French contribution to the EnVision mission
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A fleet of three missions
For its part, NASA has selected two other missions to Venus in 2021 as part of its Discovery program :
- DAVINCI (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging)
- and VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy).
On VERITAS, Observatoire de Paris-PSL is heavily involved in the design and supply of sub-systems for the VEM instrument.
Thomas Widemann, a member of the VERITAS scientific team and coordinator of the EnVision scientific team, is playing a key role in the international scientific coordination of the ’Venus decade’ which is due to begin in 2030.
Together, EnVision, DAVINCI and VERITAS will provide the most comprehensive study of Venus ever carried out.