Program Options to Explore Ocean Worlds
- Paper number
IAC-17,A7,1,6,x40185
- Author
Mr. Brent Sherwood, Caltech/JPL, United States
- Coauthor
Prof. Jonathan Lunine, Cornell University, United States
- Coauthor
Dr. Christophe Sotin, United States
- Coauthor
Dr. Thomas Cwik, United States
- Coauthor
Dr. Firouz Naderi, United States
- Year
2017
- Abstract
The next US planetary Decadal Survey’s mission priorities will emerge in 2022-23. US law already requires NASA to implement a “virtual” Ocean Worlds Exploration Program (OWEP) using a mix of mission classes. NASA and ESA are currently developing large missions to explore Europa and Ganymede, respectively; NASA is also formulating concepts for a potential large mission to search for biosignatures on the Europa surface. Small-class mission concepts for Titan and Enceladus were proposed in 2010 and 2014, but not selected; NASA awarded $25M in 16 technology-development projects pertinent to Europa and other ocean worlds; and presently (October 2017), NASA is evaluating up to four medium-class OWEP mission concepts proposed to the New Frontiers program. The Mars Exploration Program (MEP) offers a successful exemplar for a strategic program. Yet none of six key conditions underpinning the MEP over the past 15 years apply to a virtual OWEP. Disparate initiatives are unlikely to cohere into an efficient OWEP. OWEP technical challenges are formidable: 1) almost a dozen diverse ocean worlds of varying priority, with key pieces of the ocean-world scientific puzzle are distributed among them; 2) power limitations at the Jovian and Saturnian ocean worlds; 3) standard launch and in-space propulsion impose half-decade (to Jupiter) or decade-long (to Saturn) transfers; and 4) the oceans are beneath kilometers of cryogenic ice. A virtual program would also be handicapped by programmatic constraints. First, OWEP technologies outside the framework of individual missions have uncertain funding; the $25M allocated in FY17 is but a small down-payment, and enhanced investment would compete against many other solar system objectives. Second, medium-class OWEP missions would compete against unrelated science objectives in a fine-grained, non-strategic evaluation. Presently NASA has no mission-opportunity class comparable to the MEP backbone (MGS, Odyssey, and MRO, all directed, medium-class missions) that supports surface missions. Progress would be fastest if NASA could adapt three MEP program characteristics: 1) major technology investments separate from mission projects; 2) directed medium-class missions that conduct pivotal investigations on a sustained roadmap; and 3) multi-mission technical infrastructure that “lowers the bar” for individual missions. Th most important OWEP example is space transportation, e.g., the Space Launch System and high-power solar-electric propulsion, to minimize trip times into Saturn and Jupiter orbit. This analysis treats the governing programmatic constraints, technical uncertainties, and policy gaps for an OWEP, then lays out multiple options for maximizing progress on the highest priority science objectives.
- Abstract document
- Manuscript document
IAC-17,A7,1,6,x40185.pdf (🔒 authorized access only).
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