The paper addresses quaternion-based energy and time optimal spacecraft reorientation in the presence of complex attitude constrained zones. Designing an optimal reorientation trajectory for a rigid body spacecraft is posed as a nonlinear optimal control problem. In this direction, attitude constrained zones are defined with respect to the onboard instrument under two categories, forbidden and ...

This article studies the appointed-time attitude tracking control of spacecraft on special orthogonal group, with forbidden zone, parameter uncertainties, and external disturbances. A novel projection function is proposed, such that normalized boresight vector sensitive instrument mapped to a reduced dimensional in Euclidean space. If uniformly bounded, constraint zone will be satisfied at all ...

The Earth Observing 1 (EO-1) mission is part of NASA’s New Millennium Program (NMP). The EO-1 Attitude Control System (ACS) flight software was based on the Tropical Rainfall Measuring Mission (TRMM) flight software, both of which were developed by the Hammers Company, Inc. Lessons learned during TRMM ACS software development led to a consolidated software development approach for the EO-1 ACS....

This paper considers the problem of attitude synchronization control of a group of flexible spacecraft under an undirected communication graph and in the absence of measurements of both modal variables and spacecraft angular velocities. To solve this problem, a nonlinear observer is introduced to estimate the unmeasurable modal variables and spacecraft angular velocities. Then, the backstepping...