ORBITAL OPTIMIZATION OF INTERPLANETARY TRAJECTORIES WITH
ENVIRONMENTAL PERTURBATIONS
AThesis
presented to
the Faculty of California Polytechnic State University,
San Luis Obispo
In Partial Fulfillment
of the Requirements for the Degree
Master of Science in Aerospace Engineering
by
Eric Woods
June 2018 c 2018 Eric Woods ALL RIGHTS RESERVED
ii COMMITTEE MEMBERSHIP
TITLE: Orbital Optimization of Interplanetary
Trajectories with Environmental Perturba-
tions
AUTHOR: Eric Woods
DATE SUBMITTED: June 2018
COMMITTEE CHAIR: Kira Abercromby, Ph.D.
Associate Professor of Aerospace Engineering
COMMITTEE MEMBER: Colleen Kirk, Ph.D.
Professor of Mathematics
COMMITTEE MEMBER: Jordi Puig Suari, Ph.D.
Professor of Aerospace Engineering
COMMITTEE MEMBER: Eric Mehiel, Ph.D.
Professor of Aerospace Engineering
iii ABSTRACT
Orbital Optimization of Interplanetary Trajectories with Environmental Perturbations
Eric Woods
For a detailed analysis of orbital optimization, it is desired to incorporate a space- craft environment model in order to have maximum confidence that the analysis will produce an accurate trajectory. Such a model requires the addition of orbital pertur- bations, or small forces acting on the spacecraft throughout its trajectory that can eventually accumulate in large distances over time. The optimization method that this thesis is concerned with is STOpS (Spacecraft Trajectory Optimization Suite), a Matlab optimizer created by Timothy J. Fitzgerald that utilizes an Island Model
Paradigm with five di↵erent optimization algorithms. STOpS was originally built to model trajectories with the two body equations of motion. A Lambert’s method was utilized to link the spacecraft trajectory from planet to planet, and a flyby section was created for the hyperbolic gravity assist trajectories. A cost function was then used to evaluate the best combination of V, time of flight, synodcity, flyby altitude, and heliocentric energy. This work is primarily concerned with adding the dynamics created by perturbations into Lambert’s problem as well as the gravity assist trajecto- ries. The improved analysis creates a more robust solution for dealing with optimized interplanetary trajectories. Two proven trajectories will be focused on for the main analysis of this thesis which are the trajectories taken by Voyager 2 in the tour of the solar system as well as Cassini’s mission to Saturn. When perturbations were added to the analysis of these missions, STOpS was able to find trajectories which met both