Empirical basis is considered of Newtonian classical mechanics which unlike to that of Aristotle is common to terrestrial and heavenly bodies. Equations are derived for determination of the longitudinal component of the Solar system’s inertial motion by means of eclipses observations of planets’ satellites. A solution of this problem makes one of the steps towards overcoming the conflicting demands of celestial mechanics and stellar astronomy from one side and cosmonautics from the other side. Classical mechanics is sufficient to satisfy the demands of both sides.