NASA has selected the DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus) proposal to be one of two new U.S.-led missions to the planet Venus. The Discovery Program mission, which will include University of Michigan professor of climate and space sciences and engineering Sushil Atreya, was chosen after a sixteen-month Step One concept study following the downselection to four finalist investigations out of a total of about two dozen proposals submitted in June 2019. Professor Atreya will lead the origin and evolution of Venus atmosphere effort on the DAVINCI+ mission. DAVINCI+ will be the first NASA mission to study the atmosphere of Venus since 1978.
The mission is currently slated for launch in 2029 and will arrive at Venus approximately four months after launch. Upon arrival at Venus, the DAVINCI+ spacecraft will make two flybys of the planet prior to releasing the probe for descent into the atmosphere. These first passes will allow the spacecraft’s suite of cameras called VISOR (Venus Imaging System from Orbit for Reconnaissance) to study the composition of the surface of Venus as well as its atmospheric circulation by remote sensing. About two years later, DAVINCI+ will enter its prime mission phase performing in situ measurements of the atmosphere from the probe as it drops to the highlands of Alpha Regio on the dayside. The descent is expected to last about one hour.
“Venus is the missing piece of the formation and climate evolution of terrestrial planets puzzle,” said Professor Atreya. “In the past, Venus, Earth and Mars are believed to have had all the right conditions for life as we know it − surface liquid water, nutrients in the form of minerals with the essential elements of carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur (C, H, N, O, P, S), chemical and solar energy and a hospitable environment to boot, yet today only our home planet hosts life.”
Why, when and how, Earth’s twin Venus changed to a body so hot that lead would melt on its surface, an atmosphere made up of carbon dioxide with a crushing pressure 90 times greater than on Earth, no liquid water, and global clouds of sulfuric acid droplets and haze is a long-standing mystery.
“The key to the mystery is in highly precise abundances and the isotopic ratios of the noble gases, especially xenon, krypton and argon, and of water vapor, nitrogen and oxygen, along with the chemical cycles of the sources and sinks of C, H, N, O, P, S bearing molecules in the atmosphere,” said Professor Atreya. “This would allow us to look back in time to the very beginnings of the formation of Venus and how external forces such as cometary impacts and solar wind erosion together with indigenous processes such as tectonism, volcanism and runaway greenhouse effect have shaped the planet over time into being what it is today.”
The Venus Mass Spectrometer (VMS) and the Venus Tunable Laser Spectrometer (VTLS) on the DAVINCI+ probe will sniff, sample, and analyze the Venusian air dozens of times from an altitude of approximately 70 km all the way down to the surface, thus providing first highly precise measurements of the chemical abundances and the isotopic ratios. The Venus Atmospheric Structure Investigation (VASI) will measure atmospheric temperature, pressure and winds through the probe’s descent needed for context and dynamics. The Venus Descent Imager (VenDI) will take hundreds of near-infrared images of the Alpha Regio highlands, yielding an unprecedented three-dimensional map of the topography of one of the enigmatic tesserae regions that are unique to Venus.
NASA Goddard Space Flight Center has the overall responsibility for the management of the mission, as well as project systems engineering to develop the probe flight system. Goddard will build the VMS instrument in collaboration with the University of Michigan’s Space Physics Research Laboratory (SPRL).
“Ten years from now, using a carefully chosen suite of instruments with proven state-of-the-art technology DAVINCI+ is poised to revolutionize our understanding of the atmospheric origin and evolution and past or present habitability of our sister world,” said Professor Atreya. “This would serve also as a valuable guide in assessing the habitability potential of distant Venus-like exoplanets James Webb Space Telescope is expected to observe around low mass stars.
”The Venus science community and I, as first co-chair of NASA’s new Venus Exploration Analysis Group (VEXAG) from 2005-2008, have long advocated for the origin and evolution of Venus atmosphere as one of the highest priority science goals of any future NASA mission to Venus; I’m absolutely thrilled we’ll finally be able to accomplish that goal and much more with the selection of DAVINCI+.
“It’s a dream come true!”
Read more about DAVINCI+ here: https://www.nasa.gov/feature/goddard/2021/nasa-to-explore-divergent-fate-of-earth-s-mysterious-twin-with-goddard-s-davinci
Read NASA Press Release of Discovery selection here: https://www.nasa.gov/press-release/nasa-selects-2-missions-to-study-lost-habitable-world-of-venus
More about Professor Sushil Atreya here: https://www.umich.edu/~atreya