The development of scientific areas of mechanics as a result of the research of the Honorary Professor of St.Petersburg State University, Honored Worker of Science and Technology of the Russian Federation, Doctor of Physics and Mathematics Viktor Sergeevich Novoselov, the founder of the scientific school on analytical mechanics, space dynamics and applied mathematics is considered. The main theorems of analytic dynamics were extended to mechanical systems of variable composition. Using a variational technique, a number of remarkable results were obtained on the dynamics of controlled systems. In particular, a general scheme for constructing analytical approximations was proposed and repeatedly applied to solve equations.