THE EXPLORATION OF EUROPA: INNOVATIVE APPROACHES FOR EXPLORING EUROPA'S HABITABILITY

Europa may have the greatest astrobiological potential of any extra-terrestrial body in our Solar System. Unique among the large icy satellites it probably has a long-lived saltwater ocean beneath an ice shell that is geodynamically active. The combination of irradiation of its surface and tidal heating of its interior could make Europa a rich source of chemical energy for life, and direct contact of the ocean with a rocky mantle and potential hydrothermal activity could provide energy and nutrients to support biological activity. NASA has carried out numerous studies of Europa exploration concepts over the past several years, many of them with Science Definition Teams lead by Ron Greeley.

At the current time, NASA has enlisted a study team to consider Europa mission options feasible over the next decade, compatible with NASA’s projected planetary science budget and addressing Planetary Decadal Survey priorities. Two Europa mission concepts (Orbiter and multiple flyby—called the “Clipper”) are undergoing continued study with the goal to “Explore Europa to investigate its habitability.”

The Orbiter and Clipper architectures lend themselves to specific types of scientific measurements. The Orbiter concept is tailored to geophysical science that requires a spacecraft in orbit around Europa. Science goals include confirming the existence of and characterizing the ocean along with mapping of the global morphology and topography, and detailed characterization of surface features. This architecture provides for radiation-shielded instruments with low mass, power, and data rate. The Clipper concept focuses on remote sensing science that could be accomplished through multiple close flybys of Europa. Science goals include exploring the ice shell for evidence of liquid water within or beneath it along with investigating the composition of the surface and atmosphere. Morphologic and topographic mapping of specific geological features would also be carried out. This architecture can provide for radiation-shielded instruments with higher mass, power, and data rate.

We here report on the status of the current Europa exploration studies, and on the contributions of Ron Greeley to Europa exploration.