Analysis of parking orbits for round-trip Mars missions

A roundtrip mission to Mars, whether manned or unmanned, presents a great number of engineering challenges in all fields of the mission architecture. In particular, the human exploration of Mars is widely considered to be the next great frontier for space engineering. The hurdles of this type of mission vary largely, from space medicine to the project of a vehicle able to leave the Mars surface. The choice of the parking orbits around Mars, which is the subject of this thesis, is fundamental too, as it needs to ensure Mars capture and escape of the spacecraft, with the minimal expense of propellant. This translates into a necessary optimization of the total DV. In the context of this master thesis, the bi-elliptic apotwist method of parking orbits selection, developed by Qu, Merrill, Chai and Komar, is presented and analyzed. This technique consists of seven burns, including three "apotwists", namely plane change maneuvers performed at apoapsis. The bi-elliptic apotwist method performs better in terms of total DV compared to more traditional 2-burns sequence. Furthermore, it has been developed a MATLAB code that computes the optimization of the total DV of the seven maneuvers using a genetic algorithm, which theory is also presented in one of the chapters. The code's results have then been compared to pre-existing data to verify its quality and a mass estimation has been proposed.