Armadillo Aerospace is a leading developer of reusable rocket powered vehicles. They are focused on VTVL (vertical takeoff, vertical landing) suborbital research and passenger flights. The current focus is on the STIG (Suborbital Transport with Inertial Guidance) family of reusable sounding rockets designed to reduce the cost and increase the frequency of access to suborbital space for scientific payloads. STIG B's inaugural flight is scheduled for summer 2012 and already has four payloads on the manifest; three scientific payloads and one PR / advertising payload. The mission STIG B-I mission is designed for an altitude of ~120-km+ with up to four minutes of micro-G time. Additional improvements over the precursor STIG A vehicle include a more sensitive micro-G sensor suite and a cold gas thruster Attitude Control System (ACS) for more accurate pointing control of the vehicle (micro-G environment vs. centi-G environment) The objective of this proposal is to add 3-axis stabilization and pointing to the Armadillo STIG-B launch vehicle by integrating a highly accurate "Advanced Micro Sun Sensor" (AMSS) to the vehicle. Addition of AMSS to Armadillo attitude control system (ACS) combined with the Armadillo's decision to adopt a cold gas ACS will enable future scientific mission with 3 axis pointing control requirements. In particular astronomy missions that require accurate pointing to specific celestial objects or to occult the sun for surface observations and for accurate pointing at terrestrial objects / regions for agricultural or geological observations. At present, NASA FOP cannot accept ANY payloads that require tight pointing requirements because none of the qualified and available launch vehicles can offer it Addition of the AMSS that will provide the sun vector together with the on-board accelerometer that provides the gravity vector will be enable the launch vehicle a complete 3-axis attitude determination. Given this information (propagated on the gyros for ~4 minutes) and data from AMSS the 3-axis attitude information can be made available for the payload and vehicle attitude control. Analyzing the error budget it can be shown that it will be possible to control the pointing to better than 0.8 degree (1-#) The AMSS is a state of art miniaturized digital sun sensor. The AMSS has been a pathfinder for a new generation of sun sensors and has inspired a handful of other similar developments around the world and may be useful on RSLVs other than Armadillo. Publications on the AMSS have been cited 88 times according to Google Scholar. An Engineering Model (EM) of AMSS has been built, functionally tested, and qualified. A prototype unit has been balloon tested to 125,000 feet. One engineering model and 5 flight units of AMSS will be built, tested, qualified to an environment specified by Armadillo, and delivered to Armadillo for integration on their vehicle. Flight data will be collected and analyzed to determine the performance of AMSS during flight.