Multi-gravity assist design tool for interplanetary
trajectory optimisation

Abstract: Gravity assist trajectories are a crucial part of any space mission
involving interplanetary travel of spacecraft. The reason that gravity
assist is important for these missions is that they allow the spacecraft to
reach outer planets which otherwise would not be possible because of the
large amount of energy required. Gravity assist trajectories allow the
spacecraft to gain momentum from the planets. During a close approach of a
gravitational body momentum is exchanged between the spacecraft and the
gravitational body. In reality the planet loses momentum but due to the
huge mass difference the change in velocity of the gravitational body is
negligible compared to the gain in velocity of the spacecraft.
Although there exists software’s for multiple gravity assist trajectory
design but they are not readily available to the academia and have
complicated user interfaces. The ultimate goal of this thesis is to enhance
the Lambert’s problem solver tool available at the university and
incorporate the gravity assist functionality. All the technicalities of the
Lambert’s problem are presented as it is an integral part of the complete
problem. Pruning techniques are also incorporated so as to make the
software run the simulations in a reasonable amount of time.