Description: Sample return missions, by nature, require high levels of spacecraft autonomy. Developments in hardware avionics have led to more capable real-time onboard computing platforms, which allow for the implementation of more sophisticated algorithms. A real-time convex optimizer named COARSE (Convex Optimizer for Asteroid Rendezvous and Sampling Return) is proposed in order to efficiently guide path planning operations as well as spacecraft guidance and control. COARSE consists of a series of high level goals with specific set of execution steps, rather than complex interaction with ground control. This proposal plans to develop and simulate a basic optimizer for the purpose of a robotic spacecraft in proximity operations to an asteroid for a sample return mission, and implement in a spacecraft avionics software environment. If follow on Phase II work is awarded, the optimizer can be matured to expand higher levels of system complexity and constraints, potentially dealing with tasking multiple spacecraft working in coordination.

Benefits: The technology proposed is directly applicable to the needs of the NASA Technology Roadmap TA04 for spacecraft autonomy and autonomous rendezvous and docking. The current planned mission of OSIRIS-REx going to asteroid 1999 RQ36 for sample return would greatly benefit from proposed algorithms. More generally, other NASA missions to benefit would be: 1. Planetary landing missions (example Mars and Titan) 2. New Frontiers missions (Comet Surface Sample Return and Trojan Tour and Rendezvous) 3. Discovery class missions to asteroids NASA's Multi Purpose Crew Vehicle is another potential beneficiary of the COARSE technology, as it extends its operations beyond Low Earth Orbit. Our proposed work provides a novel solution to manage on-board consumables for increased mission success.

Although COARSE is proposed for robotic exploration spacecraft near asteroids, the technology can be used in spacecraft generalized to any proximity operations, rendezvous and docking, or formation control. Managing consumables is always a priority for spacecraft, regardless of size or complexity. Companies like SpaceX and others providing commercial resupply services to the ISS, as well as vehicles like HTV and ATV could benefit from the proposed software. DoD missions in Low Earth Orbit which involve spacecraft rendezvous to high level of precision navigation around cooperative or noncooperative targets would be one application of this technology (e.g. DARPA Phoenix).