Abstract <p>It is shown that extending the solution to the problem of interplanetary launch of a spacecraft from the low orbit of the departure planet backward in time generates a trajectory structurally coinciding with the virtual gravity-assist trajectory near the departure planet. The pericenters of the auxiliary bundle of flyby hyperbolas and their passage times differ only slightly from the corresponding parameters of the designed departure orbit when launching from the specified point. Thus, the search for an interplanetary transfer trajectory can be separated from the need to account for the boundary conditions of launching from an intermediate low prelaunch orbit. The prelaunch orbit is refined based on the results of a search for the interplanetary transfer trajectory. A structurally uniform scheme for the ballistic design of spacecraft flight trajectories using multiple gravity-assist maneuvers based on planetary ephemerides is presented.</p>