Neptune-Triton System Science from Neptune Odyssey

Abstract:

Neptune Odyssey is a Planetary Mission Concept Study performed by the Johns Hopkins University Applied Physics Laboratory (APL) for NASA’s Planetary Science Division’s Planetary Mission Concept Study. Odyssey would send a flagship-class spacecraft to orbit Neptune, performing system-level science, using 15 instruments on the orbiter and 8 instruments on an entry probe to address the following questions: 1. How do the interiors and and atmospheres of ice giant (exo)planets form and evolve? 2. What causes Neptune's strange magnetic field and how do its magnetosphere and aurora work? 3. Is Triton an ocean world? What causes its plumes? What is the nature of its atmosphere? 4. How can Triton's geophysics and composition expand our knowlede of dwarf planets like Pluto? 5. What are the connections between Neptune's rings, arcs, surface weathering and small moons? In our engineering point design, a $3.5 billion spacecraft would launch on an SLS rocket with a Centaur upper stage, allowing direct-to-Neptune launch opportunities every calendar year. Our example spacecraft would launch with a 3520 kg wet mass to Neptune orbit and utilize 3 RTGs, requiring 28.8 kg of Plutonium. A Jupiter gravity assist, while enhancing if utilized before 2032, is not required. Odyssey would deploy an atmospheric entry probe into Neptune, and spend four years orbiting the giant planet, flying by Triton every orbit and using the moon’s gravity to shape Odyssey’s orbital tour. Near the mission’s conclusion, Odyssey would perform a Cassini-like Grand Finale, diving between the rings and the planet before it is disposed into Neptune. We present our mission concept as a “shovel-ready,” Concept Maturity Level of 4: this is a mission NASA could choose to do now without waiting for significant advances in technology. Finally, equipping both the orbiter and probe with cameras specially-purposed for public engagement will help to share the joy of exploration and discovery with those who help make space exploration possible—the US taxpayer.