A Concept for space mission to icy moon: Small probes for a subsurface ocean exploration mission to Europa

This thesis focuses on a concept of space mission to icy moon, based on small probes with large radiogenic heat source. Icy moons could be the best candidates for the next space mission because there is possible to find liquid water and the conditions to host life. The attention of this paper is focused on Europa. Europa is an icy moon of Jupiter with a subsurface ocean of liquid water. Since water is one of the fundamental ingredients for life, its study has gained a lot of interest within the science community. Recently, concepts for a probe, which could potentially melt though Europa’s ice shell, have been discussed in the open literature. To date, these concepts have mainly focused on a single probe design that makes use of a relatively large radiogenic heat source based on plutonium-238. However, due to Europa’s relatively low temperature (100 K), low atmospheric pressure (0.1 μPa) and low gravity (g=1.35 m/s2), smaller probe designs with higher thermal power densities are could play a significant role to help overcome the challenges associated with ice sublimation and refreezing. In this paper, new smaller melting probe designs are examined that make use of radiogenic heat sources with higher thermal power density. Specifically, designs that utilize curium-244 and uranium-232 are assessed. Probes with relatively small lengths (0.20-1.50 m) and small radii (0.06-0.12 m) are considered and compared with different melting velocities and radioisotopes. Different concepts are studied for the communication problem.