<h2>AAS  96-177</h2><h2>ON IMPROVING THE GALILEO SCAN PLATFORM CONE CONTROLLER PERFORMANCE IN CRUISE MODE REMOTE SENSING</h2><h4>C-H. C. Ih, K. B. Hilbert, E. H. McMahon, and K. A. Bahrami, Jet Propulsion Laboratory</h4><h2> Abstract </h2>Ambiguous images of the star Regulus were observed during the calibration of Galileo instruments in December 1989.  Analysis showed that this was caused by the very sluggish scan platform response to the slew command in the cone direction, and in turn this sluggish cone performance was due to inadequate cruise mode cone control gains. Thus the cruise mode cone control gains were redesigned. Simulation results demonstrated that significantly improved scan platform cone performance is achievable with the new gains under various slew and friction conditions. The new gains are scheduled to be uplinked to the spacecraft in March of 1996.<br><br>