In order to identify the distinctive features of using analog and digital control systems, a comparative analysis of kinematic parameters of movement of two space rockets was carried out. Relying on the external trajectory measurement data, we developed a method for calculating the estimates of statistical characteristics of isochronous variations in the parameters of the state vector of the space rockets. Within the study, we compared and analyzed the kinematic parameters of the movement of Soyuz-FG and Soyuz-2 1a space rockets. Using the external trajectory measurement data, we calculated the spacecraft initial orbit parameters formed by the considered launch vehicles, and estimated their accuracy. Findings of research show that the parameters of the initial orbit formed by Soyuz-2 have smaller deviations from their nominal values, unlike the launch trajectory of the previous generation launch vehicle. Experimental data have confirmed the positive contribution of terminal control to reducing deviations of the implemented trajectory from the nominal one.