Envision Mission science activities and status

Envision is ESA’s next mission to Venus and was adopted in January 2024. Thales Alenia Space Itay (TAS-I) was awarded the contract to build the spacecraft in December 2024, initiating the mission implementation. The launch is scheduled for the early 2030s, and the start of the science operations at Venus is expected in mid 2030s, 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 science objectives will be addressed by five instruments and one experiment, provided by ESA member states and NASA. The NASA S-band Synthetic Aperture Radar contribution is, however, at the time of writing highly uncertain, and ESA is therefore investigating alternative European S-band SAR technologies for the targeted (repeat) surface imaging, polarimetric and stereo imaging, radiometry, and altimetry. The procurement of the high-frequency Subsurface Radar Sounder (SRS) is lead by ASI, and the instrument 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. Their procurements are led by CNES, BELSPO and DLR. 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. Its science related procurement is led by CNES. All instruments have heritage and robust margins relative to the requirements for operations at Venus, and were chosen to meet the broad range of measurement requirements needed to support the Envision scientific objectives. The science teams will adopt an open data policy, with public release of the scientific data in the ESA Planetary Science Archive (PSA) after validation and verification. Public calibrated data availability is <6 months after data downlink.

ESA is starting a competitive Phase B1 for a European SAR instrument in summer 2026. In parallel, a European SAR Instrument Science Team is being appointed to support ESA and the Envision Science Working Team (SWT) for the European SAR design finalization. Furthermore, new SWT working groups have started to work on the scientific preparation of the mission in the areas of Venus surface Regions of Interest, Envision aerobraking science, Venus atmosphere science, Venus surface, subsurface and interior science, and Venus spin state science. In this presentation, the scientific objectives and the status will be provided, including an overview of on-going scientific activities in the working groups and beyond.