Maffione Porzia Federica

Politecnico di Torino
Italy

Title: Analysis of launch opportunity for low-thrust interplanetary missions

Biography

Abstract

Interplanetary missions are strictly dependent on the launch opportunity. Mission planning requires a knowledge not only of the technological and cost constraints but also the study of the influence of the launch opportunity on the spacecraft performance and on the feasibility of the mission itself. Porkchop plots are very effective tools to design an interplanetary mission, providing a graphical and optimized overview of the relationship between the fundamental parameters of the mission design: the launch date, the duration and the energy. In this way it is possible to evaluate the best region to accomplish the mission under current constraints. Porkchop plots in their usual implementation are, however, applicable only to impulsive (chemical or NTP) propulsion. In this paper an interplanetary mission from Earth to Mars is analyzed, comparing plots similar to porkchop plots, but obtained for low thrust, NEP and SEP. As a first approximation, the orbits of the two planets are considered as coplanar and circular. Then, using the ephemerides, elliptical and non coplanar orbits are taken into account and the “ideal” plots are compared with the actual ones, referred to a particular launch opportunity. Finally, some numerical examples are carried out.