The reach of cyber-physical systems into space is growing exponentially, as launch services proliferate and satellites have become small, cheap, and capable. Unlike expensive satellites of the past, the near future promises constellations of thousands of inexpensive nanosatellites. Nanosatellites are becoming capable of supporting space-based cyber-physical applications, including defense, smart cities, agriculture, & infrastructure, climate science, and search & rescue. Unfortunately, nanosatellites today operate like monolithic satellites of the past, manually operated at high cost, impeding the realization of the potential of nanosatellites for these important cyber-physical systems applications. This project envisions a new operating model for space-based cyber-physical systems in nanosatellite constellations called a "software-defined nanosatellite constellation", which unleashes their potential. A software-defined constellation is a collection of nanosatellites capable of autonomously sensing the environment, processing data, and cooperatively planning and taking mechanical actions. The project realizes this vision through cross-cutting cyber-physical systems research spanning computer systems, control, planning, actuation, machine learning, and communications. This project will culminate in the launch of a software-defined constellation testbed that implements several space-based applications, demonstrating these societally important capabilities and applications, and functioning as a valuable resource for other cyber-physical systems researchers.

This CPS Frontier project is establishing nanosatellite constellations as sophisticated, multi-tenant platforms for space-based cyber-physical systems applications. The work is interdisciplinary, spanning controls, ML, communications, systems, and hardware. The project makes constellations autonomous and equipped to compute efficiently on orbit. On-orbit computing treats constellation-level satellite control and actuation as resource management for unique nanosatellite resources: sensor data, bandwidth, energy, and computing. On-orbit machine learning techniques bring federated learning to the constellation, creating an autonomous orbital learning system. The project?s new communication techniques extract maximum information from each bit communicated, combining weak signals and often avoiding communication altogether. The project demonstrates the project?s value with on-orbit infrastructure and testbeds that form an open platform for future space-based cyber-physical systems research. The project will have a broad, transformative impact on society, industry, and education, within and beyond the cyber-physical and space systems communities. Software-defined nanosatellite constellations create an industry of cost-effective space-based applications. The project eliminates barriers to space, enabling industry to develop space-based applications. The project creates a new field of research around space-based cyber-physical systems fostering research and education. This project includes ambitious education activities from middle school to post-graduate levels. The project team will mentor middle schoolers and high schoolers from urban public schools through space systems research internships. The project team will involve undergraduates and graduate students in research mentoring and new curricula. The proposed outreach activities will engage society broadly via artist-in-residence programs, research community-building, and public/academic/private partnerships.