A simple approach for predicting time-optimal slew capability

• Published in: Acta astronautica Vol. 120; pp. 159 - 170
• Main Authors: King, Jeffery T., Karpenko, Mark
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2016
• Subjects: Agile spacecraft; Agility envelope; Arrays; Eigenaxis slews; Estimating; Optimal control; Reaction wheels; Satellite imagery; Satellites; Simulation; Spacecraft; Three dimensional; Time-optimal attitude maneuvers; Reaction wheels; Time-optimal attitude maneuvers; Agility envelope; Agile spacecraft; Eigenaxis slews
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2015.12.009

The productivity of space-based imaging satellite sensors to collect images is directly related to the agility of the spacecraft. Increasing the satellite agility, without changing the attitude control hardware, can be accomplished by using optimal control to design shortest-time maneuvers. The performance improvement that can be obtained using optimal control is tied to the specific configuration of the satellite, e.g. mass properties and reaction wheel array geometry. Therefore, it is generally difficult to predict performance without an extensive simulation study. This paper presents a simple idea for estimating the agility enhancement that can be obtained using optimal control without the need to solve any optimal control problems. The approach is based on the concept of the agility envelope, which expresses the capability of a spacecraft in terms of a three-dimensional agility volume. Validation of this new approach is conducted using both simulation and on-orbit data. •We present a simple approach for predicting time-optimal manuever slew time.•This estimate can be obtained without the need to solve the optimal control problem.•The approach is based on the spacecraft agility envelope.•We validated the approach against thousands of optimal control solutions.•Results also validated with on-orbit implementation of time-optimal slews.