P31A-1884: Optimizing Decadal and Precursor Science on Small Solar System Bodies with Spacecraft/Rover Hybrids
Authors: Marco Pavone1, Julie C Castillo2, Jeffrey A Hoffman3, Issa A Nesnas2, Nathan J Strange2
Author Institutions: 1. Aeronautics and Astronautics, Stanford University, Stanford, CA, USA; 2. Jet Propulsion Laboratory, Caltech, Pasadena, CA, USA; 3. Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, MA, USA
In this paper we present a mission architecture for the systematic and affordable in-situ exploration of small Solar System bodies (such as asteroids, comets, and Martian moons). The proposed mission architecture stems from a paradigm-shifting approach whereby small bodies’ low gravity is directly exploited in the design process, rather than being faced as a constraint. At a general level, a mother spacecraft (of the type of JPL’s NEOSurveyor) would deploy on the surface of a small body one, or several, spacecraft/rover hybrids, which are small (<5Kg, ~10W), multi-faceted robots enclosing three mutually orthogonal flywheels and surrounded by external spikes (in particular, there is no external propulsion). By accelerating/decelerating the flywheels and by exploiting the low gravity environment, the hybrids would be capable of performing both long excursions (by hopping) and short traverses to specific locations (through a sequence of controlled "tumbles"). Their control would rely on synergistic operations with the mother spacecraft (where most of hybrids' perception and localization functionalities would be hosted), which would make the platforms minimalistic and in turn the entire mission architecture affordable. A fundamental aspect of this mission architecture is that the responsibility for primary science would be shared between the mothership and the hybrids, in particular, the mothership would provide broad area coverage, while the hybrid would zoom in on specific areas and conduct in-situ measurements. Specifically, in the first part of the paper we discuss the scientific rationale behind the proposed mission architecture (including traceability matrices for both the mothership and the hybrids for a number of potential targets), we present preliminary models and laboratory experiments for the hybrids, we present first-order estimates for critical subsystems (e.g., communication, power, thermal) and a preliminary study for synergistic mission operations, and we discuss high-level mission trades (including deployment strategies). In the second part, we tailor our mission architecture to the exploration of Mars' moon Phobos. The mission aims at exploring Phobos' Stickney crater, whose spectral similarities with C-type asteroids and variety of terrain properties make it a particularly interesting exploration target to address both high-priority science for the Martian system and strategic knowledge gaps for the future Human exploration of Mars.