Ocean Worlds Exploration and the Search for Life

Abstract

We recommend the establishment of a dedicated Ocean Worlds Exploration Program within NASA to provide sustained funding support for the science, engineering, research, development, and mission planning needed to implement a multi-decadal, multi-mission program to explore Ocean Worlds for life and understand the conditions for habitability. The two new critical flagship missions within this program would 1) land on Europa or Enceladus in the decade 2023-2032 to investigate geophysical and geochemical environments while searching for biosignatures, and 2) access a planetary ocean to directly search for life in the decade 2033-2042. The technological solutions for a landed mission are already in-hand, evidenced by the successful delta-Mission Concept Review of the Europa Lander pre-flight project in the fall of 2018. Following an initial landed mission, an ocean access mission will require substantial research, development, and analog testing this decade to enable the initiation of a pre-flight project at the start of the following decade. This ambitious goal could not have been put forward with comparable, requisite credibility in any preceding decade. Both science and technology have now matured so that we may prioritize the direct search for signs of life, applying lessons learned from planetary and Earth exploration to in situ investigations of worlds where water and life are most likely to exist today. This new era of planetary investigation will require significant support for cross-disciplinary research and development, bringing together planetary scientists and engineers with those that study the Earth. To chart these new waters, a diversity of disciplines must be accompanied by a diversity of experience, skill, and perspective. All facets of this Ocean Worlds Exploration Program must actively ensure equitable access and inclusion across the spectrum of contributors in Planetary Science, Exploration, and Astrobiology. Hence, we recommend an Ocean Worlds Exploration Program that includes specific initiatives designed to entrain and retain scientists and technologists from historically under-represented groups and to support a healthy work-life balance that enables equitable participation from across the entire community.

Planetary Oceanography: Leveraging Expertise Among Earth and Planetary Science

“…In its recent publication, Origins, Worlds and Life (NASEM, 2022), the National Academies' Planetary Science & Astrobiology Decadal Survey made a series of recommendations that would afford exciting further opportunities for ocean worlds investigations. Many of these align closely with ideas proposed by the Network for Ocean Worlds (Howell et al, 2021). In addition to recommendations to increase NASA budgets within the Planetary Science Division (PSD) in the areas of Technology (to 6%-8% of PSD's annual budget) and Research and Analysis (to 10% of PSD's annual budget), there are also specific recommendations related to the field of astrobiology that emphasize a future focus on the important areas of systems level thinking, subsurface habitability, and the development of life detection technology (NASEM, 2022).…”

Resurfacing: An Approach to Planetary Protection for Geologically Active Ocean Worlds

“…The amount of surface that is potentially contaminated by the space mission upon contact with the ocean world, in both nominal and off-nominal scenarios. As future missions pursue more and more ambitious investigations of these worlds, including the potential fly-through of water vapor plumes, in situ exploration of their surfaces (Hand et al 2017;MacKenzie et al 2020), and deep subsurface exploration of their ice and oceans (Howell et al 2021b), this requirement will continue to be a challenging constraint to consider. Because this model can be implemented conservatively with limited information about the body, this approach may be especially suitable for considering missions to potentially habitable, active ocean worlds and potential ocean worlds that are poorly observed, such as Neptune's moon Triton or the Uranian satellites.…”

Surviving in Ocean Worlds: Experimental Characterization of Fiber Optic Tethers across Europa-like Ice Faults and Unraveling the Sliding Behavior of Ice

“…Conditions on Europa and other icy Ocean Worlds are considerably different from terrestrial conditions. Characterizing these ice shell environments at the surface and in the interior will provide key engineering and design constraints for ice and ocean access technologies under development and help retire associated technological risks (Howell et al 2020). In this section, we explore the environmental conditions expected in Europa's ice shell, which motivate the design of our laboratory experiments and constrain the test parameters, as described in Section 3.…”