Drill for Acquisition of Complex Organics for Dragonfly Mission

Drill for Acquisition of Complex Organics (DrACO) is a sample acquisition and delivery system for the Dragonfly New Frontiers mission to explore Titan. The goal of the mission is to assess Titans habitability and investigate its prebiotic chemistry. Dragonfly is an octocopter lander and will perform numerous vertical takeoffs and landings to pre-scouted locations. At each site, Dragonfly will have the option to use DrACO sampling system to acquire Titan surface material for detailed compositional analysis. Selected in June 2019, Dragonfly is scheduled to launch in 2027 and arrive on the Titan surface in the mid-2030s. The purpose of the DrACO system is to capture Titan surface and near-surface material and deliver it to DraMS (Dragonfly Mass Spectrometer). DraMS operates in two measurement modes: Laser Desorption Mass Spectrometer (LDMS) and Gas Chromatograph Mass Spectrometer (GCMS). DrACO consists of four major subsystems: The Sample Acquisition Drills (SAD), the Pneumatic Transport System (PTS), the Sample Delivery Carousel (SDC), and associated Avionics. Material is suctioned directly through the drill bit, and pneumatically conveyed in a fast-moving stream of ambient Titan air. This helps to minimize temperature rise, reducing risk of sample alteration or fouling of the transport system. In contrast to traditional sample transfer systems, the DrACO pneumatic architecture is gravity agnostic. The end-to-end system features two sampling drills, which offers site selection capabilities at a single site, and two redundant suction blowers in a cross-strapped configuration: either drill can deliver sample to either LDMS or GCMS cups using either blower. Pneumatic sample collection has 5 advantages: (1) The delivery point can be at a distance from the drill, because the connecting tube can be routed around the vehicle. (2) Sample temperature remains cold during transfer because the transport medium is 94K Titan air. (3) Sample transfer does not rely on gravity, a strong advantage if moving cohesive material. (4) Cross-contamination is significantly reduced by running air through the pneumatic lines prior to and after sample transfer. (5) Risk of clogging is minimized because sample remains in motion until captured by the LDMS and GCMS sample cups or exhausted outside the lander. Extensive testing was performed to characterize the behavior of a range of Titan simulants (both room temperature and cryogenic analog materials) during drilling, transport and collection.