The MAI-400SS Space Sextant is a precision attitude determination and control system for CubeSats and Nanosats. The MAI-400SS enables future CubeSat missions with precision fine pointing (0.1deg) and dynamic slewing as will be required for imaging operations of ground targets. A flight control computer, 2 Star Trackers, 3 reaction wheels and 3 electromagnets are incorporated in a 4" x 4" x 3" (3/4U) CubeSat sized module. The system is based on the highly successful MAI-400 miniADACS and extends its performance capability to the 0.1deg range by incorporation of 2 star cameras and attitude determination software. Phase I developed the software algorithms and prototyped the star cameras and electronics. Phase II consists of a development program culminating with a system at TRL 7. The technology is significant because it extends the capability of current low cost Nanosats to tactical imaging and other missions requiring fine pointing and dynamic retargeting, missions hitherto restricted to large and expensive spacecraft. The MAI-400SS will facilitate rapid development of low cost satellites by providing a turnkey system which would be capable of determining and controlling spacecraft attitude automatically; simplifying operations and enabling rapid mission development as envisioned by ORS.