The Joint ESA-NASA Venus Science Coordination Group (VESCOOR) to support the three Venus Missions

Kurzfassung

The selection of three new missions to Venus opens a new era to explore the planet and its evolution: ESA’s EnVision and NASA’s VERITAS and DAVINCI missions plan to observe Venus in the next decade. ESA and NASA established a joint Venus Science Coordination group (VeSCoor) as a forum for dialogue within the broader Venus scientific community, in support of the upcoming ESA and NASA missions to Venus [1]. The NASA VERITAS mission will study the surface and interior with an interferometric synthetic aperture radar and infrared instrument that provide global topography, imaging, rock type, and targeted surface deformation, plus radio science for interior structure [2]. The NASA DAVINCI mission a descent probe that will determine the composition and history of Venus’ atmosphere as well as make additional measurements of the planet’s surface and atmosphere. DAVINCI consists of a spacecraft hosting a carrier and a descent probe, with seven in-situ, imager and spectrometer instruments [3]. EnVision, an ESA orbital mission in collaboration with NASA, will simultaneously investigate Venus’ history, activity and climate, from its inner core, to its surface, and further up to its upper atmosphere. EnVision’s science payload consists of five instruments (radar, spectrometers, sounding radar and radio science experiment) [4]. These missions will offer unprecedented complementary views of Venus and determine fundamental characteristics of the planet and its long term evolution [5, 6]. In this scenario, VeSCoor’s primary goals are to identify new, unanticipated scientific approaches and outcomes based on synergies among the missions to Venus and suggest studies to enhance overall scientific return. However, VeSCoor will not evaluate or propose changes to the current mission profiles, scientific objectives, or requirements. The group was initially made up of 12 members from the Venus science community (Figure 1), 6 selected by ESA and 6 by NASA, plus 3 representatives of the EnVision, VERITAS and DAVINCI missions [7]. Membership in VesCoor is initially set to a 2 year term, but may be renewed at the discretion of NASA and ESA. A scientific observer from South Korea has subsequently joined the group along with two members selected by JAXA. VeSCoor members’ expertises cover different scientific disciplines to provide a comprehensive view of Venus as a planet, and hence, as a complex system. Representatives from NASA and ESA agencies are involved as observers to provide support to the group’s activities. The Group meets in-person twice a year to discuss science objectives and receive updates on the missions’ development. The outcomes of the discussion will be part of public documents available soon. Three working groups (Interiors, Surfaces, and Atmospheres) have been created to address the identified topics, and to discuss specific actions that could facilitate progress in advance of the missions. The first in-person meeting was held in February 2024 in Virginia, USA (Figure 2). Mission representatives from VERITAS, EnVision, and DAVINCI presented descriptions of mission science payloads, timelines, expected science returns, and current activities. VeSCoor members worked on developing the "Rules of the Road" document that establishes rules of conduct and communication. The second in-person meeting of VeSCoor was held in the ESA ESTEC establishment on November 2024 (Figure 3). We included in the discussion the Earth-based observation of Venus and talked about the Korean earth-based satellite for Venus exploration (CLOVE) [8]. To improve the scientific discussion, four speakers were invited to present specific topics identified by the Group as strategic: - Sara Seager presented the ‘The search for life in the Venus’ clouds’ goal of the Morning Star mission. - Sebastien Lebonnois presented a review on the Venus Global Climate Models. - Edgar Steenstra talked about his recent laboratory set up to support the EnVision observations. - Lorenzo Bruzzone, PI of the radar Sounder SRS onboard EnVision presented the objectives and foreseen capabilities of this instrument to explore the subsurface of Venus. The third in-person meeting of VeSCoor was again held at the Lansdowne Resort in Leesburg in March of 2025 (Figure 4). The group received updates on NASA developments from Delia Santiago-Matarese, and status reports from EnVision, VERITAS, and DaVinci mission leadership. Three speakers were invited this time: - David Grinspoon (NASA’s Senior Scientist for Astrobiology Strategy) discussed the Astrobiological Potential of Venus. - Michael Chaffin presented the Photochemical Hydrogen Loss from Venus and the Fate of an Earth-like Water Inventory. - Debra Buczkowski described the status of the Venus Geologic Mapping Efforts. The preliminary results of the discussion emphasize the importance of on-going studies and experimental work in preparation for the new missions. The importance of completing the Venus mapping programme and generating ongoing discussion on common mapping standards for the international Venus community was emphasized. Also, facilitation of analog field studies to test the instrument performance, operational routine and scientific data integration was supported. International collaboration is fundamental to unite the efforts for successful exploration of Venus. The Group also discussed the need to establish workshops for the international Venus community (COSPAR, etc.) and maintain contact with other Venus-focused groups (i.e., VEXAG).