Yuri Shimane
(Advisor: Prof. Koki Ho)
will defend a doctoral thesis entitled,
Modeling, Optimization, and Validation of In-Space Facility Location Problem
on
Wednesday, May 21 at 9:00 a.m.
CODA C1015 Vinings
756 West Peachtree Street, Atlanta, GA 30332
Abstract
This thesis is centered on in-space facility location problems (FLPs). The FLP provides a general 
framework to consider the placement and allocation of in-space assets, for applications ranging 
from in-space servicing to cislunar space situational awareness. Compared to terrestrial problems, 
in-space applications require considerations of the underlying  orbital  mechanics  and  the  
associated  nonlinear,  potentially  time-varying performance metrics. This thesis presents general 
considerations to determine whether a static or a time-expanded in-space FLP formulation is 
appropriate for the application at hand; then, example space-based problems for both static and 
time-expanded cases are provided. With the time-expanded FLP, where the problem dimension becomes 
particularly large due to the time dependency of performance metrics and, consequently, of the 
allocation decisions, a customized Lagrangian relaxation algorithm together with a set of 
specialized heuristics is proposed.
In the context of cislunar infrastructures, libration point orbits (LPOs) provide relatively stable 
and geometrically diverse orbits for assets to be located. Motivated by the significantly lower 
number of existing missions in cislunar libration point orbits (LPOs), this thesis also provides 
orbital validation of LPOs in a high-fidelity ephemeris model (HFEM). The validation consists of two 
steps: first, the nominal ballistic and quasi-ballistic design problem is considered through an 
optimal control approach. Then, station-keeping along the designed baseline in the presence of 
uncertainties and operational constraints is studied. A targeting model predictive control scheme, 
suitable for both ballistic and quasi-ballistic baselines, is devised and demonstrated to provide 
satisfactory station-keeping performance, both in terms of cumulative cost and tracking deviation, 
over extended durations.
Committee
•  Prof. Koki Ho – School of Aerospace Engineering (advisor)
•  Prof. Glenn Lightsey – School of Aerospace Engineering
•  Prof. John Christian – School of Aerospace Engineering
•  Dr. Dario Izzo – European Space Agency
•  Dr. Gregory Badura – Georgia Tech Research Institute