Integrated Stellar Gyroscope for Visual Attitude Propagation on Small Satellites

Attitude Determination is critical for many CubeSat class satellites, and is generally a major factor in the utility of small satellites in general. The mass, volume, and power constraints of the CubeSat form factor limit the options available to designers. We are developing a visual attitude propagation approach to generate spacecraft relative attitude estimates in three degrees of freedom without the drift associated with most solid state based gyroscope approaches. A stellar gyroscope is a visual star-based attitude propagator that uses relative motion of stars in an imager’s field of view to infer the attitude changes. In previous work by the Space Systems Laboratory (SSL), the concept has been proposed, the feasibility of the approach has been proven, practical applications have been identified, and prototype hardware has been used to test the system in controlled experiments. The camera system is a technology demonstration experiment on KySat-2, a CubeSat developed in Kentucky, launching in 2013 on the NASA ElaNa-III mission. In this work, we will develop an integrated stellar gyroscope. Software will be developed to implement the stellar gyroscope algorithm on the embedded platform. This will entail defining the software interface and writing a function library that implements the visual attitude propagation approach on the embedded platform, to provide the attitude measurements in real-time (where analysis to this point was based on post-processing). In collaboration with the NASA Marshall Space Flight Center, the integrated stellar gyroscope will be interfaced to the attitude determination and control system being developed there.