The Regolith Biters: A Divide-And-Conquer Architecture for Sample Return Missions

The concept investigated consists of a space mission architecture for collecting multiple, distributed samples from small, primitive celestial bodies (like asteroids and comets) and bringing them back to Earth for their study; It is fundamentally different from existing alternatives because it is based on the premise that separating the navigation problem from the sample collection problem will lead to a more robust and flexible overall system. The current architectural paradigm for sample-return missions is centered around a design where spacecraft and sampling device are merged into a single, complex system; we argue that this monolithic approach couples the navigation and sample-collection problems, making both more difficult. We diverge from this vision, and propose a decoupled system-based on the coordinated interaction between a spacecraft and a collective of small, simple devices, which we have called the Regolith Biters(RBs). A spacecraft carrying a number of RBs would travel to the vicinity of a small body. From a favorable vantage point, and while remaining at a safe distance on a non-colliding trajectory, it would release an approach stage capable of delivering the RBs towards the target body. Upon encountering the body, the RBs would bite the regolith (thus retaining a sample), and eject back to a heliocentric orbit. The spacecraft, being endowed with appropriate propulsion, navigation and tracking capabilities, would rendezvous with and collect those RBs within its reach, and bring them back to Earth. Separating the navigation and sampling concerns could remove the need for proximity operations with the small body---the stage in current architectures that carries the most challenges and risks. Eliminating the need for small body proximity operations brings back to the discussion the exploration of exciting prospects like highly active comets, fast-rotating bodies, and binary systems. In addition, distributing the sampling problem among a collective of agents could provide the opportunity to sample multiple regions ---on one or multiple bodies within a system - in a single mission. It may also provide robustness to various environmental conditions, and enable the distributed, in-situ characterization of the small body. These technical distinctions separate our concept from existing art.