The AggieSat3 mission aimed to demonstrate close proximity navigation utilizing a stereo vision system in an advancement toward autonomous rendezvous and docking missions.
AggieSat3 was Texas A&M University’s spacecraft mission for the Air Force Research Laboratory’s Nanosat-5 program. AggieSat3 is a collaborative effort between Texas A&M University, the National Aeronautics and Space Administration, and Embry Riddle Aeronautical University. The primary goal of this mission was aimed at advancing sensor technologies for use in future Autonomous Rendezvous and Docking missions. AggieSat3 will serve as the testbed for a stereo-vision system called the Bumblebee2. This system, which was developed at Point Grey Research Inc., features two high resolution cameras that provide imagery in a similar manner to one’s eyes. Through image analysis, distance to and from a secondary object can be determined. For space applications, this system could serve as an impact avoidance system or an attitude and orientation identification tool. AggieSat3 hoped to evaluate its use for the latter during its mission. This research will have the added benefit of aiding the LONESTAR program with its final goal of autonomously rendezvousing two orbiting spacecraft.
In addition to testing its revolutionary stereoscopic space navigation technique, AggieSat3 also carried a set of GPS receivers developed by NASA, and a debris detector developed by ERAU. Serving as a secondary mission objective, AggieSat3 was required to record GPS data during the stereoscopic navigation period to achieve differential tracking solutions. This information must then be transmitted to the ground, along with the imagery data to verify the experimental results. Again, this system will help support the LONESTAR program in its ARD objectives. Students at AggieSat Lab have teamed up with students from Embry Riddle Aeronautical University for AggieSat3’s third payload, a space debris detector. This detector, which was developed at ERAU, flew with AggieSat3 during its mission. As AggieSat3 orbits around the Earth, data was planned to be collected from the detector and transmitted down with the imagery and GPS data from AggieSat3’s two other missions.
AggieSat3 was also AggieSat Lab’s first satellite with full attitude determination and control capabilities. Using a combination of three torque coils and three reaction wheels, the A&M satellite was capable of re-orienting itself while in orbit to maximize solar power acquisition and keep a selected target in its field of view during tracking exercises.
Aiming to achieve overarching AggieSat Lab objectives, AggieSat3 was developed as a reconfigurable bus which can be supportive of future missions planned by AggieSat Lab. Many of the successes of AggieSat1 were carried on into this new mission including the command and data handling and client software packages. Utilizing these previous systems as building blocks for the AggieSat3 system l not only expedited the design process but allowed for more robust system development as well. This method will also be useful in achieving the Lab’s objective of developing a Responsive Space Missions architecture. With the advancement of these software packages and its stereo-vision navigation techniques, AggieSat Lab hoped to pave the way for future missions with its AggieSat3 satellite.
To ensure AggieSat3 met the expectations of the Air Force and AggieSat Lab administrators, a time line was constructed to establish critical deadlines that had to be met for project completion. These deadlines were both internal requirements, and requirements stated in the Nanosat V competition established by the Air Force.