Aerospace Instrument-Making Annotation << Back The Particular Case of Optimal Attitude Control of a Spacecraft Based on the Quaternions Levskii M.V. Quaternion solution of the problem on optimum control of a turn of a spacecraft (as solid body) from an arbitrary initial into an assigned fi nal angular position with minimal loading of the construction is presented. Optimization of orientation control is based on quadratic criteria of quality. Integral of functional takes into account kinetic factor that interpretations as dynamic loads. Analytical solution of optimal control problem is obtained with use of quaternionic models of the solid body motion controlled. The properties of optimal motion are formulated and described in an explicit form. To construct optimal control program, formalized equations and calculation formulas are written. Analytical equations and relations for finding optimal control are given. Key relationships de-termining optimal values of the parameters of control algorithm for rotation are presented. In the case of axially symmetric loading of spacecraft, solution to the reorientation problem is obtained in closed form. A numerical example and results of mathematical simulation which confirm the practical feasibility of the developed method of spacecraft’s attitude control reorientation are given. Keywords: quaternions, attitude control, control function, maximum principle, the conjugate variables, control algorithm, the boundary-value problem. DOI: 10.25791/aviakosmos.2.2026.1534 Pp. 03-12.