EnVision will be ESA’s next orbit of Venus, providing a comprehensive view of the planet from its inner core to the upper atmosphere to determine how and why Venus and Earth evolved so differently.
The mission was selected by the ESA Scientific Program Committee on June 10 as the fifth mid-range mission in the Space Vision Agency’s plan to launch in the early 2030s.
“A new era awaits us in the study of the closest, but wildly different, neighbor of the solar system,” said Günther Hassinger, director of science at ESA. “Along with the recently announced NASA-led missions to Venus, we will have an extremely comprehensive scientific program on this mysterious planet over the next decade.”
A key question in planetary science is why, although roughly the same size and composition, our neighbor in the inner solar system is experiencing such dramatic climate change: instead of being an inhabitable world like Earth, it has a toxic atmosphere and is surrounded by sulfuric acid-rich rich clouds. What history did Venus go through to reach this state, and does this predict the fate of the Earth if it also suffers a catastrophic greenhouse effect? Is Venus still geologically active? Could he ever have hosted the ocean and even sustained life? What lessons can we learn about the evolution of terrestrial planets in general as we discover more Earth-like exoplanets?
EnVision’s innovative toolkit will address these big issues. It will be equipped with a set of European instruments, including an echo sounder for detecting underground layers and spectrometers for studying the atmosphere and the surface. The spectrometers will monitor traces of gases in the atmosphere and analyze the surface composition, looking for any changes that may be associated with signs of active volcanism. NASA-provided radar will map and map the surface. In addition, a radio science experiment will study the internal structure and gravitational field of the planet, as well as the structure and composition of the atmosphere. The tools will work together to best characterize the interaction between the planet’s various boundaries – from the interior to the surface to the atmosphere – providing a comprehensive global view of the planet and its processes.
EnVision follows from ESA’s hugely successful Venus Express (2005-2014), which focuses primarily on atmospheric research, but also made dramatic discoveries that point to possible volcanic hotspots on the planet’s surface. JAXA’s Akatsuki spacecraft has also been studying the atmosphere since 2015. EnVision will significantly improve surface radar images obtained by NASA’s Magellan in the 1990s. Working together with the upcoming missions DAVINCI + (Deep Atmosphere Venus Investigation of Noble gasses, Chemistry and Imaging) and VERITAS (Venus Emissionsvity, Radio Science, InSAR, Topography, and Spectroscopy), the trio of new spacecraft will provide the most comprehensive study of Venus ever. .
“EnVision is taking advantage of the collaboration with NASA, combining excellence in European and American experience in Venus’ science and technology, to create this ambitious mission,” says Gunther. “EnVision further strengthens Europe’s role in solar system research. Our growing mission fleet will give us, as well as future generations, the best insight into how our planetary neighborhood works, especially in an age where we are discovering more and more unique exoplanetary systems. “
“We are excited to contribute to ESA’s exciting new mission to explore Venus,” said Thomas Zurbuchen, NASA’s Associate Science Administrator. “EnVision uses its strengths in developing tools from both our agencies. Combined with NASA’s Venus Discovery missions, the scientific community will have a powerful and synergistic set of new data to understand how Venus formed and how its surface and atmosphere have changed over time. “
Following the initial call for the fifth concept for a mid-range mission in 2016, the final race boils down to EnVision and Theseus, the transitional high-energy sky, and the early universal surveyor. Theseus will observe transient events across the sky, and in particular will focus on the gamma rays of the first billion years of the universe to help shed light on the life cycle of the first stars. While EnVision was recommended by the Senior Scientific Committee, it was acknowledged that Theseus also has an extremely convincing scientific case that can make an extremely important contribution in this area.
The next step for EnVision is to move on to the detailed “Definition Phase”, in which the design of the satellite and instruments is finalized. Following the design phase, a European industrial contractor will be selected to build and test the EnVision before it is launched on the Ariane 6 rocket. The earliest opportunity to launch the EnVision is 2031, with other possible options in 2032 and 2033. The spacecraft will take about 15 months to reach the planet, and another 16 months will reach the circulation of the orbit through aerobarking. Its 92-minute orbit will be quasi-polar with an altitude of between 220 and 540 km.
Solar Orbiter, Euclid, Plato and Ariel have already been selected for middle-class missions. Solar Orbiter launched in February 2020; Euclid, Plato and Ariel will be on the market throughout this decade.
EnVision is led by an ESA mission with important contributions from NASA, which will provide VenSAR (Synthetic Aperture Radar) as well as support for the Deep Space Network. The remaining payload instruments are provided by the ESA Member States, with ASI, DLR, BelSPO and CNES managing the supply of SRS (Underurface Sounding Radar), VenSpec-M, VenSpec-H and VenSpec-U spectrometers, respectively. The radio science experiment is led by institutes in France and Germany.