 | |
| Mission type | Venus orbiter |
|---|---|
| Operator | European Space Agency |
| Website | esa.int/.../Envision |
| Mission duration | Planned: 4.5 years |
| Spacecraft properties | |
| Launch mass | 2,607 kg (5,747 lb) |
| Dry mass | 1,277 kg (2,815 lb) |
| Payload mass | 255 kg (562 lb) |
| Power | 2.35 kilowatts |
| Start of mission | |
| Launch date | December 2031 (planned)[1] |
| Rocket | Ariane 64[1] |
| Launch site | KourouELA-4 |
| Contractor | Arianespace |
| Venus orbiter | |
| Orbital insertion | 2034[2] |
| Orbital parameters | |
| Pericytherion altitude | 220 km |
| Apocytherion altitude | 470 km |
| Transponders | |
| Band | X-band,Ka-band[3] |
← ARIEL | |
EnVision is an orbital mission toVenus being developed by theEuropean Space Agency (ESA) that is planned to perform high-resolutionradar mapping and atmospheric studies.[4][3]EnVision is designed to help scientists understand the relationships between its geological activity and theatmosphere, and it will investigate why Venus and Earth took different evolutionary paths. The probe was selected as the fifth medium mission (M5) of ESA'sCosmic Vision programme in June 2021,[2] with launch planned for December 2031.[1] The mission will be conducted in collaboration withNASA.[5]
In the early 2020s, a new fleet ofVenus missions was announced byNASA andESA. Missions under development include ESA'sEnVision orbiter mission, NASA'sVERITAS orbiter mission, and NASA'sDAVINCI entry probe/flyby mission. The data acquired with these missions from the end of the decade are expected to fundamentally improve our understanding of the planet's long term history, current activity, and evolutionary path.[6][7]
The scientists who submitted theEnVision proposal in response to the call for proposals for the M5 mission of ESA's Cosmic Vision program are Richard Ghail ofRoyal Holloway,University of London, UK, Colin Wilson, Department of Physics,University of Oxford, UK, Thomas Widemann,LESIA,Observatoire de Paris andUniversité de Versailles-Saint-Quentin, France, and others.[8][9]
On 10 June 2021, the mission was selected by ESA's Science Programme Committee as the fifth M-class mission in theCosmic Vision programme. It was selected overTHESEUS (Transient High-Energy Sky and Early Universe Surveyor), an astrophysics mission proposal that would monitor transient events, especiallygamma-ray bursts, across the whole sky.[10]
Technical preparatory work onEnVision was being conducted even before the mission's official adoption by ESA. For example, in July 2022, the Low Earth Orbit Facility (LEOX) facility atESTEC was testing materials and coatings from the spacecraft to simulate the condition duringaerobraking at Venus.[11]
EnVision was officially adopted by ESA's Science Programme Committee in January 2024[12] and in January 2025, ESA awarded a contract toThales Alenia Space to build the spacecraft as the mission's prime contractor.[13]
In 2025,NASA's participation inEnVision came into question after the Republican administration released a budget request for NASA for the fiscal year 2026, which included drastic cuts to the agency's science programmes. ESA's Director of ScienceCarole Mundell announced thatEnVision was among three ESA missions (together withLISA andNewAthena) most impacted by this potential budget reduction on the US side and that "recovery actions" would be required.[14][15]
EnVision will deliver new insights into geological history through complementary imagery, polarimetry, radiometry and spectroscopy of the surface coupled with subsurface sounding and gravity mapping; it will search for thermal, morphological, and gaseous signs of volcanic and other geological activity; and it will trace the fate of key volatile species from their sources and sinks at the surface through the clouds up to the mesosphere.[16] Core science measurements include: high-resolution mapping of specific targets, surface change, geomorphology, topography, subsurface, thermal emission,SO
2,H
2O, D/H ratio, gravity, spin rate, and spin axis.
The specific mission goals are:[3][6]
In 2025, ESA formulated the mission goals as "top five questions" thatEnVision aims to solve:[17]
TheEnVision orbiter will be a rectangular,3-axis stabilised spacecraft of 2 m x 2 m x 3 m in stowed configuration. Energy will be provided by two deployablesolar arrays. Communication with Earth will be provided by a fixed 2.54 m diameter High Gain Antenna. The high thrust required byEnVision's mission profile will be provided by abi-propellant ~1kN main engineLEROS 4 withspecific impulse of ~320s.[18]
EnVision is an ESA mission in collaboration with NASA, and contributions from individual ESA member states for the provision of payload elements. NASA is contributing the VenSAR instrument and supplies theDeep Space Network support. The other payload instruments are contributed by ESA member states, with ASI, DLR, BelSPO, and CNES leading the procurement of SRS,VenSpec-M, VenSpec-H, and VenSpec-U instruments respectively.[19][3][6]
Thesynthetic aperture radar VenSAR will characterise structural and geomorphic evidence of multi-scale processes that shaped the geological history of Venus, as well as characterise current volcanic, tectonic, and sedimentary activity.[20] The instrument will operate at 3.2GHz in theS-band (9.4 cm wavelength).[20] VenSAR will provide several imaging and ranging techniques from a polar orbit: (1) regional and targeted surface mapping, (2) global topography and altimetry, (3) stereo imaging, (4) surfaceradiometry andscatterometry, (5) surfacepolarimetry, (6) repeat passinterferometry opportunities. TheJet Propulsion Laboratory's instrument selected by NASA is currently undergoing scientific, technical and mission assessment.[20] The principal investigator of the VenSAR isScott Hensley,JPL.[21]
SRS will be a fixed dipole antenna operating in the range 9–30 MHz. SRS will search for subsurface material boundaries in various geological terrains that include impact craters and their infilling, buried craters, tesserae and their edges, plains, lava flows and their edges, and tectonic features to provide stratigraphic relationships at various depth ranges and horizontal scales. The principal investigator of the SRS is Lorenzo Bruzzone,Università di Trento, Italy.[19]
VenSpec will consist of three channels:VenSpec-M, VenSpec-H, and VenSpec-U.VenSpec-M will provide compositional data on rock types, VenSpec-H will perform extremely high resolution atmospheric measurements, and VenSpec-U will monitor sulfured minor species (mainlySO andSO2), as well as the mysterious UV absorber in the Venusian upper clouds. This suite will search for temporal variations in surface temperatures and tropospheric concentrations of volcanic gases, indicative ofvolcanic eruptions.
The principal investigator of the Venus Spectroscopy suite and PI ofVenSpec-M is Jörn Helbert, DLR Institute of Planetary Research, Berlin, Germany. The PI of VenSpec-H is Ann Carine Vandaele, RoyalBelgian Institute for Space Aeronomy (BIRA/IASB), Belgium. The PI of VenSpec-U is Emmanuel Marcq, LATMOS, IPSL, France.[19]
In March 2025, the company Xenics announced an agreement withDLR to provideshort-wave infrared sensors forEnVision's VenSpec-M instrument, as well as for NASA's Venus missionVERITAS.[22][23][24]
VenSpec-H is being developed and built by a consortium of four companies (led by TRL Space) inBrno,Czechia, in collaboration with theCzech Academy of Sciences. The 2.6 million euro contract was awarded in July 2025.[25] The instrument will carry a silhouette ofVenus of Vestonice, anUpper Paleolithic ceramicVenus figurine discovered in 1925 inSouth Moravia and on display at theMoravian Museum inBrno.[26]
Any orbiting spacecraft is sensitive to the local gravity field, plus the gravity field of the Sun and, to a minor extent, other planets. These gravitational perturbations generate spacecraft orbital velocity perturbations, from which the gravity field of a planet can be determined.EnVision's low-eccentricity, near-polar, and relatively low altitude orbit offers the opportunity to obtain a high-resolution gravity field at each longitude and latitude of the Venusian globe.[19]
The analysis of the gravity field together with the topography gives insights on the lithospheric and crustal structure, allowing to better understand Venus's geological evolution. In the absence of seismic data, the measurements of the tidal deformation and proper motion of the planet provide the way to probe its deep internal structure (size and state of the core). The tidal deformation can be measured in theEnVision orbital velocity perturbations through the gravitational potential variations it generates (k2 tidal Love number).
The co-Principal Investigators ofEnVision Radio Science and Gravity experiment are Caroline Dumoulin, LPG,Université de Nantes, France, and Pascal Rosenblatt, LPG, Université de Nantes, France.[19]
EnVision was still planning a launch in December 2031. ESA recently changed the launch vehicle for the mission from an Ariane 62 to an Ariane 64.
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