NASA scientists must not have had an easy decision this winter, as they considered more than a dozen intriguing concepts for Discovery-class missions to explore the solar system.
But they decided they did, and Thursday selected four missions for additional study and refinement. NASA said the proposals were chosen based on their potential scientific value and feasibility of development plans, through a competitive peer-review process.
Each of the mission teams will now receive $3 million from NASA to complete its proposals over a nine-month period. After this, NASA will likely select two missions to further develop and launch later in the 2020s. Discovery missions have a cost cap of $450 million.
The space agency chose the following four mission concepts for further research and provided the following summaries of their capabilities.
The mission seeks to analyze Venus’ atmosphere to understand how it formed and evolved before determining whether Venus ever had an ocean. The spacecraft will dive through Venus’ inhospitable atmosphere to accurately measure its composition all the way to the surface. The instruments are encased in a purpose-built descent sphere to protect them from the intense environment of Venus. The “+” in DAVINCI+ refers to the mission’s imaging component, which includes descender and orbiter cameras designed to map surface rocks. James Garvin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator. Goddard would provide project management.
Io Volcano Observer
This mission would explore Jupiter’s moon Io to learn how tidal forces form planetary bodies. Io is heated by the constant crushing of Jupiter’s gravity and is the most volcanically active body in the solar system. Little is known about the specifics of Io, such as whether a magma ocean exists inside. Using close-in flybys, IVO would assess how magma is generated and erupted on Io. The results of the mission could revolutionize our understanding of the formation and evolution of rocky, terrestrial bodies, as well as icy ocean worlds in our solar system and extrasolar planets in the Universe.
Alfred McEwen of the University of Arizona at Tucson is the principal investigator. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, would provide project management.
Trident would explore Triton, a unique and highly active icy moon of Neptune, to understand pathways to habitable worlds vast distances from the sun. NASA’s Voyager 2 mission showed that Triton has active resurfacing — generating the second-youngest surface in the solar system — with the potential for erupting plumes and an atmosphere. Coupled with an ionosphere that can create organic snow and the potential for an inner ocean, Triton is an exciting exploration target for understanding how habitable worlds might evolve in our solar system and others. Using a single flyby, Trident would map Triton, characterize active processes and determine whether the predicted subsurface ocean exists. Louise Prockter of the Lunar and Planetary Institute/Universities Space Research Association in Houston is the principal investigator. NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, would provide project management.
This mission seeks to map the surface of Venus to determine the planet’s geologic history and understand why Venus evolved so differently from Earth. VERITAS orbits Venus with a synthetic aperture radar, mapping surface elevations across almost the entire planet to create three-dimensional reconstructions of topography and confirm whether processes, such as plate tectonics and volcanism, are still active on Venus. VERITAS would also map infrared emissions from the surface to map the geology of Venus, which is largely unknown. Suzanne Smrekar of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, is the principal investigator. JPL would take care of the project management.
In particular, two of the four missions are focused on Venus. NASA’s last mission to Venus was Magellan, an orbiter launched in 1989. If selected, the DAVINCI+ mission would be the first NASA-led spacecraft to enter the planet’s atmosphere since 1978. Both Venus missions were finalists in the final call for Discovery-class missions – announced in January 2017 – missing from the final version. Both selected missions at the time, Lucy and Psyche, were devoted to the study of asteroids.
Perhaps Venusian lovers will do better this time.