Some Verification Issues at NASA Goddard Space Flight Center

Abstract

NASA is developing increasingly complex missions to conduct new science and exploration. Missions are increasingly turning to multi-spacecraft to provide multiple simultaneous views of phenomena, and to search more of the solar system in less time. Swarms of intelligent autonomous spacecraft, involving complex behaviors and interactions, are being proposed to accomplish the goals of these new missions. The emergent properties of swarms make these missions powerful, but simultaneously far more difficult to design, and to verify that the proper behaviors will emerge. In verifying the desired behavior of swarms of intelligent interacting agents, the two significant sources of difficulty are the exponential growth of interactions and the emergent behaviors of the swarm. NASA Goddard Space Flight Center (GSFC) is currently involved in two projects that aim to address these sources of difficulty. We describe the work being conducted by NASA GSFC to develop a formal method specifically for swarm technologies. We also describe the use of requirements-based programming in the development of these missions, which, it is believed, will greatly reduce development lead-times and avoid many of the problems associated with such complex systems.