Payload Systems Inc. (PSI) and the MIT Space Systems Laboratory (MIT-SSL) propose an innovative research program entitled SPHERES-ISS that uses their satellite formation flight laboratory (Synchronized Position Hold Reorient Experimental Satellites - SPHERES), currently operating aboard the International Space Station (ISS), to refine and validate NASA Goddard Space Flight Center's (GSFC) Pluribus algorithms. Pluribus supports "multiple systems in simultaneous, tightly-coupled, non-quiescent operations, such as robotic servicing and formation flying." SPHERES-ISS supports the same by providing a unique and cost-effective technology validation approach for algorithmic technologies that support robotic servicing and formation flight. This proposal is particularly relevant to SBIR Topic Area O1.02 Precision Spacecraft Navigation and Tracking by providing a pathway for maturing and validating technologies that are fundamental to multi-vehicle missions that support NASA's Vision for Space Exploration. . These include command and control of modular, replicated systems, robotic Earth and space science formation flown missions, in-space assembly, automated rendezvous and docking, formation flown sparse apertures, and the development of concepts of operations for such systems (e.g., software uplink protocols, required telemetry sets, fault detection and isolation).