Abstract: This work is a continuation of the review dedicated to the 300th anniversary of St. Petersburg State University (SPbSU) and is an attempt to analyze the scientific achievements of the St. Petersburg School of Mechanics in the field of rigid-body dynamics. This third part of the review is devoted to a fifty-year period ending in 2023. It focuses on applied research carried out by scientists from St. Petersburg State University in the 1970s and devoted to the uncontrolled attitude motion of a rigid body in the gravitational and magnetic fields of the Earth. A significant place among these studies is occupied by the solution of problems related to the passive gravitational stabilization of spacecraft using magnetic interaction to create restoring and damping torques. © Pleiades Publishing, Ltd. 2024. ISSN 1063-4541, Vestnik St. Petersburg University, Mathematics, 2024, Vol. 57, No. 3, pp. 307–321. Pleiades Publishing, Ltd., 2024. Russian Text The Author(s), 2024, published in Vestnik Sankt-Peterburgskogo Universiteta: Matematika, Mekhanika, Astronomiya, 2024, Vol. 11, No. 3, pp. 455–476.