Objectives and status of the Envision Venus mission

EnVision is ESA’s next mission to Venus in partnership with NASA, where NASA provides the VenSAR instrument and mission support to critical phases. ASI, DLR, BelSPO, and CNES lead the procurements of the SRS, VenSpec-M, VenSpec-H and VenSpec-U instruments and the Radio Science Experiment (RSE), respectively. The mission was adopted in January 2024, and Thales Alenia Space (TAS) was awarded the contract to build the spacecraft in January 2025. The launch is scheduled for 2031, and the start of the science operations at Venus is expected in mid-2034, following the mission cruise and aerobraking phase around Venus to achieve a low Venus polar orbit.

The scientific objective of EnVision is to provide a holistic view of the planet from its inner core to its upper atmosphere, studying the planets history, activity and climate. EnVision aims to establish the nature and current state of Venus’ geological evolution and its relationship with the atmosphere. EnVision’s overall science objectives are to: (i) characterize the sequence of events that formed the regional and global surface features of Venus, as well as the geodynamic framework that has controlled the release of internal heat over Venus history; (ii) determine how geologically active the planet is today; (iii) establish the interactions between the planet and its atmosphere at present and through time. Furthermore, EnVision will look for evidence of past liquid water on its surface.

The nominal science phase of the mission will last six Venus cycles (~four Earth years), and ~210 Tbits of science data will be downlinked using a Ka-/X-band communication system. The VenSAR S-band radar will perform targeted surface imaging as well as polarimetric and stereo imaging, radiometry, and altimetry. The high-frequency Subsurface Radar Sounder (SRS) will perform novel sounding of the upper crust in search of material boundaries. The three spectrometers, VenSpec-U, VenSpec-H and VenSpec-M, operating in the UV and Near-IR, will map trace gases, search for volcanic gas plumes above and below the clouds, and map surface emissivity and composition. The Radio Science Experiment (RSE) will exploit the spacecraft Telemetry Tracking and Command (TT&C in Ka-/X bands) system to determine the planet’s gravity field and to sound the structure and composition of the middle atmosphere and cloud layer in radio occultation. All instruments have Venus heritage and robust margins relative to the requirements, allowing the mission to meet its scientific objectives. The EnVision science teams will adopt an open data policy, with public release of the scientific data after validation and verification. Public calibrated data availability is <6 months after data downlink.

The Envision Science Working Team (SWT) have recently compiled a list of prioritized Venus targets used to create the Regions of Interest (ROIs) to be observed by the mission. The missions scientific objectives, instrumentation, and status will be presented together with a first version of the ROIs, on-going scientific and technical maturity activities, and the next steps in the mission preparation.