J. B. Garvin, S. A. Getty, G. N. Arney, N. M. Johnson, E. Kohler, K. O. Schwer, M. Sekerak, A. Bartels, R. S. Saylor, V. E. Elliott, C. S. Goodloe, M. B. Garrison, V. Cottini, N. Izenberg, R. Lorenz, C. A. Malespin, M. Ravine, C. R. Webster, D. H. Atkinson, S. Aslam, S. Atreya, B. J. Bos, W. B. Brinckerhoff, B. Campbell, D. Crisp, J. R. Filiberto, F. Forget, M. Gilmore, N. Gorius, D. Grinspoon, A. E. Hofmann, S. R. Kane, W. Kiefer, S. Lebonnois, P. R. Mahaffy, A. Pavlov, M. Trainer, K. J. Zahnle, and M. Zolotov. Revealing the Mysteries of Venus: The DAVINCI Mission. , 3(5):117, May 2022. [ bib | DOI | arXiv | PDF version | ADS link ]
The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission described herein has been selected for flight to Venus as part of the NASA Discovery Program. DAVINCI will be the first mission to Venus to incorporate science-driven flybys and an instrumented descent sphere into a unified architecture. The anticipated scientific outcome will be a new understanding of the atmosphere, surface, and evolutionary path of Venus as a possibly once-habitable planet and analog to hot terrestrial exoplanets. The primary mission design for DAVINCI as selected features a preferred launch in summer/fall 2029, two flybys in 2030, and descent-sphere atmospheric entry by the end of 2031. The in situ atmospheric descent phase subsequently delivers definitive chemical and isotopic composition of the Venus atmosphere during an atmospheric transect above Alpha Regio. These in situ investigations of the atmosphere and near- infrared (NIR) descent imaging of the surface will complement remote flyby observations of the dynamic atmosphere, cloud deck, and surface NIR emissivity. The overall mission yield will be at least 60 Gbits (compressed) new data about the atmosphere and near surface, as well as the first unique characterization of the deep atmosphere environment and chemistry, including trace gases, key stable isotopes, oxygen fugacity, constraints on local rock compositions, and topography of a tessera.
B. Charnay, G. Tobie, S. Lebonnois, and R. D. Lorenz. Gravitational atmospheric tides as a probe of Titan's interior: Application to Dragonfly. Astronomy Astrophysics, 658:A108, February 2022. [ bib | DOI | arXiv | PDF version | ADS link ]
Context. Saturn's massive gravity is expected to causes a tide in Titan's atmosphere, producing a surface pressure variation through the orbit of Titan and tidal winds in the troposphere. The future Dragonfly mission could analyse this exotic meteorological phenomenon. Aims: We aim to analyse the effect of Saturn's tides on Titan's atmosphere and interior to determine how pressure measurements by Dragonfly could constrain Titan's interior. Methods: We model atmospheric tides with analytical calculations and with a 3D global climate model (the IPSL-Titan GCM), including the tidal response of the interior. Results: We predict that the Love numbers of Titan's interior should verify 1 + ℜ(k2 - h2) -0.5ex0.02-0.1 and ℑ(k2 - h2) < 0.04. The deformation of Titan's interior should therefore strongly weaken gravitational atmospheric tides, yielding a residual surface pressure amplitude of only -0.5ex5 Pa, with a phase shift of 5-20 h. Tidal winds are very weak, of the order of 3 10-4 m s-1 in the lower troposphere. Finally, constraints from Dragonfly data may permit the real and the imaginary parts of k2 - h2 to be estimated with a precision of 0.01-0.03. Conclusions: Measurements of pressure variations by Dragonfly over the whole mission could give valuable constraints on the thickness of Titan's ice shell, and, via geophysical models, its heat flux and the density of its internal ocean.
S. Rodriguez, S. Vinatier, D. Cordier, G. Tobie, R. K. Achterberg, C. M. Anderson, S. V. Badman, J. W. Barnes, E. L. Barth, B. Bézard, N. Carrasco, B. Charnay, R. N. Clark, P. Coll, T. Cornet, A. Coustenis, I. Couturier-Tamburelli, M. Dobrijevic, F. M. Flasar, R. de Kok, C. Freissinet, M. Galand, T. Gautier, W. D. Geppert, C. A. Griffith, M. S. Gudipati, L. Z. Hadid, A. G. Hayes, A. R. Hendrix, R. Jaumann, D. E. Jennings, A. Jolly, K. Kalousova, T. T. Koskinen, P. Lavvas, S. Lebonnois, J.-P. Lebreton, A. Le Gall, E. Lellouch, S. Le Mouélic, R. M. C. Lopes, J. M. Lora, R. D. Lorenz, A. Lucas, S. MacKenzie, M. J. Malaska, K. Mandt, M. Mastrogiuseppe, C. E. Newman, C. A. Nixon, J. Radebaugh, S. C. Rafkin, P. Rannou, E. M. Sciamma-O'Brien, J. M. Soderblom, A. Solomonidou, C. Sotin, K. Stephan, D. Strobel, C. Szopa, N. A. Teanby, E. P. Turtle, V. Vuitton, and R. A. West. Science goals and new mission concepts for future exploration of Titan's atmosphere, geology and habitability: titan POlar scout/orbitEr and in situ lake lander and DrONe explorer (POSEIDON). Experimental Astronomy, January 2022. [ bib | DOI | arXiv | PDF version | ADS link ]
In response to ESA's “Voyage 2050” announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn's largest moon Titan. Titan, a “world with two oceans”, is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan is also one of the few places in the Solar System with habitability potential. Titan's remarkable nature was only partly revealed by the Cassini-Huygens mission and still holds mysteries requiring a complete exploration using a variety of vehicles and instruments. The proposed mission concept POSEIDON (Titan POlar Scout/orbitEr and In situ lake lander DrONe explorer) would perform joint orbital and in situ investigations of Titan. It is designed to build on and exceed the scope and scientific/technological accomplishments of Cassini-Huygens, exploring Titan in ways that were not previously possible, in particular through full close-up and in situ coverage over long periods of time. In the proposed mission architecture, POSEIDON consists of two major elements: a spacecraft with a large set of instruments that would orbit Titan, preferably in a low- eccentricity polar orbit, and a suite of in situ investigation components, i.e. a lake lander, a “heavy” drone (possibly amphibious) and/or a fleet of mini-drones, dedicated to the exploration of the polar regions. The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. The exploration of Titan's northern latitudes with an orbiter and in situ element(s) would be highly complementary in terms of timing (with possible mission timing overlap), locations, and science goals with the upcoming NASA New Frontiers Dragonfly mission that will provide in situ exploration of Titan's equatorial regions, in the mid-2030s.