Technology drivers and challenges for next generation distributed spacecraft systems

Distributed spacecraft systems is envisioned to provide the technology platform to extend, improve and enable mission concepts such as wide aperture radars for high-precision space-borne surveillance, 3D mapping of Earth's magnetic field and even deep-space interferometry to better understand the origins of the universe. However, a mission with a fully autonomous spacecraft fleet flying in close-proximity or in a tightly kept configuration has yet to be realized. In this work, we review the major technology drivers and challenges for such next generation systems across a selective set of on-going, cancelled or proposed space missions. Our analyses identify five main classes of technology drivers from navigation and control perspective. These drivers are enumerated for a typical interferometric SAR example. The example illustrates steep technological challenges such as the need for sub-millimeter relative navigation solution accuracy for even decimeter level vertical image resolution. We conclude with an initial effort at outlining a cost effective and robust roadmap for flight maturation of the key technologies to deem such missions and goals achievable.