Session
Technical Session VI: Attitude Control Systems
Abstract
High performance Earth sensing for spin-stabilized vehicles can be achieved through a straightforward modification to a flight-proven conical Earth horizon sensor. The necessary hardware and therefore, cost and weight is essentially identical to hardware used by three-axis stabilized satellites making precision attitude sensing available to the entire spacecraft community, including small satellite builders. The Barnes Engineering Commandable Rate Scanner uses a rotating sensor on a spinning spacecraft to provide full-sky (4x steradian) Earth coverage with a single sensor. The sensor provides data for any spacecraft attitude and altitude from LEO to above GEO. In LEO, a data rate of several hundred horizon crossings per minute is typical, allowing for extremely accurate (better than 0.02 deg) attitude sensing. In addition, the principal biases which normally dominate attitude determination accuracy for spinning spacecraft are either eliminated or can be measured. Computational complexity is low, and example algorithms for sensor data processing are provided. Simulation results show that the sensor performs well even in the presence of substantial spacecraft nutation.
The Commandable Rate Scanner: Precision Attitude Sensing for Spinning Spacecraft
High performance Earth sensing for spin-stabilized vehicles can be achieved through a straightforward modification to a flight-proven conical Earth horizon sensor. The necessary hardware and therefore, cost and weight is essentially identical to hardware used by three-axis stabilized satellites making precision attitude sensing available to the entire spacecraft community, including small satellite builders. The Barnes Engineering Commandable Rate Scanner uses a rotating sensor on a spinning spacecraft to provide full-sky (4x steradian) Earth coverage with a single sensor. The sensor provides data for any spacecraft attitude and altitude from LEO to above GEO. In LEO, a data rate of several hundred horizon crossings per minute is typical, allowing for extremely accurate (better than 0.02 deg) attitude sensing. In addition, the principal biases which normally dominate attitude determination accuracy for spinning spacecraft are either eliminated or can be measured. Computational complexity is low, and example algorithms for sensor data processing are provided. Simulation results show that the sensor performs well even in the presence of substantial spacecraft nutation.
