This Thesis presents the analysis of a descent maneuver to the Martian
moon Phobos, treated mathematically as a Low-Thrust Optimal Control
Problem. In order to increase the accuracy of the problem, the gravity
acceleration at each of the trajectory nodes is obtained by applying the
Polyhedron method, discussed in Chapter 2.
The following document is structured by discussing rst the general aspects
of the problem analyzed, focusing then completely on the Optimal
Control Problem solved.
Firstly, the scienti c aims that a mission to Phobos presents are discussed,
together with the uncertainties that are still present when studying a mission
to this Martian moon. Then, a theoretical approach to the Polyhedron
method is discussed, as well as the reasons by which this method is
chosen ahead of others.
From that point on, a closer approach to the problem is made; rst,
by making a general theoretical discussion about the numerical methods
present in the GPOPS program that could be used to solve the problem
stated, reasoning then the election made and the aspects that have
prevailed for this decision to be taken. Subsequently, a detailed characterization
of both the dynamical and path constraints implemented is made,
as well as a brief description of the propulsive parameters chosen and the
reference frame selected, in the same fashion as other articles [1] that treat
a descent maneuver too.
Finally, the analysis is centered exclusively on the solving process followed.
The computational work carried out is explained rst, detailing
the modi cations made in order to overcome the computational resources'
problem that arose. The results for the optimization are then presented,
making a thorough description of the physical phenomena occurring in
the spacecraft dynamics. As concluding remarks, a summary of the results obtained is made, together
with their limitations; a roadmap for future work is added too,
setting the steps that should be taken in the future for making an even
more realistic study, which could be used as a rst pragmatic approach to
propose a real mission to Phobos.Ingeniería Aeroespacia
