SLUSH: Europa hybrid deep drill

Europa is the primary target of Astrobiology in our Solar System because its ocean has all the necessary ingredients (water, chemicals, energy) to support extant life. Reaching Europa's ocean requires penetrating through up to 30km of partially cryogenic ice, salts, and frozen sulphuric acid. There are two primary methods of penetrating ice: mechanical and thermal. Each of these methods has unique advantages and disadvantages but neither are sufficient to reach the ocean independently. SLUSH Drill (Search for Life Using Submersible Heated Drill) is a hybrid drilling system that combines the best features of mechanical and thermal probes. It uses both energy-efficient mechanical drilling to cut through dirty cryogenic ice (e.g. ice with sediment or salt) and thermal power to partially melt ice cuttings into slush. This slush allows cuttings to flow out of the way and refreeze behind the probe. Once SLUSH passes through the cryogenic layer (∼5km thick), it can melt through the warm ice underneath without the need for mechanical cutting. SLUSH is a self-contained probe with on-board electronics and instruments. It has several Pu-based heat sources (General Purpose Heat Source) to keep itself warm and melt the ice cuttings. Electrical power and communication is transmitted by the surface lander, via an umbilical stored within the probe which unspools and freezes in the ice.