Analysis of the viability of using a sequence of gravitational maneuvers at the opposite points of the planet orbit

The insertion of the spacecraft for the study of the Sun into a heliocentric orbit with a large inclination to the plane of the solar equator with one gravitational maneuver near the Earth and as well as a sequence of four gravitational maneuvers near Venus is analyzed. The transport system is based the "Soyuz-2.1b" launch vehicle, the chemical upper stage "Fregat" and the electric propulsion (EP) with one SPT-140 thruster. The upper stage ensures the departure of the spacecraft from the Earth. EP provides heliocentric flight Earth-Earth. After the first three Venus's gravitational maneuvers, it is used the orbits with the following sequence of resonances: 1:1; 1.5:1.5; 1:1. The inclusion of an orbit with a 1.5:1.5 resonance in the flight pattern made it possible to significantly reduce the time required for a transport operation (from 5 years to 3.5 years). © 2021, Univelt Inc. All rights reserved.