Enceladus Vent Explorer Mission Architecture Trade Study

This paper presents the architecture trade study for the Enceladus Vent Explorer (EVE) mission concept, which would enable access to the potentially habitable subsurface ocean of Enceladus by traveling down the vent. A previous study (Ono et al. 2017) found that such a mission is technically feasible except for an extreme case where the largest vent on Enceladus has a diameter < 10 cm. However, the study did not investigate whether the EVE mission is implementable within realistic constraints on launch mass, cost, and risk in the foreseeable future. Our team performed a mission architecture trade study to determine whether an implementable mission architecture exists. The trade study considered alternatives in instrumentation, mobility systems, sampling strategies, landing location, and the number of spacecraft elements. As a result, we found that EVE is implementable within Flagship mission launch mass and cost constraints but that the probability of mission success is low because of high environmental uncertainty. Our study highlights the criticality of future work along two thrusts. First, EVE would benefit from the continued development of several key technologies, including high-power tethers, miniaturization of instrumentation for chemical and biological analysis, autonomous mobility, and precision landing. Second, the substantial uncertainties in Enceladus environment conditions need to be reduced to have high confidence in mission success. We recommend that, regardless of mission-specific scientific goals, future missions to Enceladus should collect data to reduce the uncertainty in several key environmental parameters in order to reduce risk for a future vent exploration mission like EVE.