The article describes the motion modeling of a rocket stage of an aerospace system based on a carrier aircraft used as the first stage and a light-class launcher as the second and third stages. This withdrawal scheme provides a number of advantages, such as the ability to select the desired starting point (the airport is based), the reduction of gravitational and aerodynamic losses, and the possibility of multiple use of system elements.

The paper analyzes the aerospace system based on the “M-55 Geophysics” as the carrier aircraft and the modified upper stages of the “Start-1” launcher with a start mass of 7.5 tons. Using the M-55 as a first stage of a launch vehicle can provide a launch speed of 200 m/s at an altitude of 17 km. The paper proposes a four-dimensional parameterization of the launch vehicle control law and selects optimal parameters for obtaining the highest altitude of a circular geocentric orbit at a fixed payload mass (the spacecraft mass  is 100 kg). The maximum height of the launch orbit ( h=203.0 km) is provided by the following control parameters: the initial, maximum and final values of the pitch angle are 0.6 deg, 47.30 deg and 34.95 deg, respectively, and the duration of the passive section is 138.3 seconds.