Star sensor mounting for highly agile Earth imaging satellite

Star sensor (SS) is one of the most critical instrument on-board a spacecraft when it comes to attitude determination and control. Capability of providing precise attitude information makes it even more important for high resolution imaging satellite with stringent pointing requirements. At the same time, these instruments are highly sensitive to bright objects like Sun and Earth Albedo. In this paper, selection of star sensor mounting has been elaborately studied and presented for missions primarily performing highly agile Earth imaging. This paper addresses selection factors like Sun and Earth avoidance from bore-sight axis, orbit altitude and local time, angular separation between SS, sensitivity of SS on body axis and functional availability during imaging. Results are presented in the form of available mounting options and the way they satisfy geometrical constraints over a year.