The aim of this paper is to discuss E-sail-based missions (E-sail – electric solar wind sail) towards Venus and Mars. The analysis takes into account the real three-dimensional shape of the starting and arrival orbits and the planetary ephemeris constraints by using the Jet Propulsion Laboratory (JPL) planetary ephemerides model DE405/LE405.
Each mission scenario is parameterized with different values of departure date and spacecraft characteristic acceleration, the latter representing the maximum propulsive acceleration when the Sun–spacecraft distance is 1 au. The transfer trajectories are studied in an optimal framework, using a Gauss pseudospectral method in which the initial guesses for the state and control histories are obtained with a genetic algorithm-based approach.
The paper illustrates the numerical simulations obtained with a spacecraft characteristic acceleration of 1 mm/s2, and the results cover a range of launch dates of 17 years for both Earth–Mars and Earth–Venus interplanetary missions. In particular, the numerical results confirm the competitiveness of such a propellantless propulsion system.
A parametric study of the transfer’s flight time corresponding to the optimal departure dates is discussed for different values of the spacecraft characteristic acceleration. The results motivate a further in-depth analysis of the E-sail concept.
This paper extends previous work on optimal trajectories with an E-sail in that the best launch opportunities are investigated. A refined thrust model is also used in all numerical simulations.
