Research

Single Vehicle Martian Cycler Trajectories - 2021 AAS Astrodynamics Specialists Conference

A new Earth-Mars cycler architecture is introduced in the form E-M-M-E-E. This itinerary has two short legs for human travel between the planets and two long phasing legs, one from Earth to Earth and one from Mars to Mars. Due to the two short legs the system only requires one vehicle for a round trip mission. The problem is parameterized with 3 time of flight terms and one geometric term leading to a denser solution space at the expense of higher dimensionality. A framework is developed for solving and optimizing the problem with a focus on quick interchangeability to allow for fast design and analysis.

A Novel Method for Comparing Interplanetary Trajectories for Early Mission Design - 2022 AAS Astrodynamics Specialists Conference

Tisserand plots are widely used in early mission design to plan interplanetary trajectories, especially ones with gravity assists. These plots, however, do not include information about transfer time. This paper presents a new method of analysis that produces plots which include transfer time as well as departure and arrival excess velocity. This method will allow mission designers to better compare and select trajectories based on all of the relevant design parameters. This paper also presents methods for optimizing these trajectories according to the three design variables, transfer time, departure excess velocity, and arrival excess velocity. 

A Uranus Mission Design Demonstrating a Simulated Annealing Algorithm - 2023 AAS Space Flight Mechanics Meeting

The planetary decadal survey has indicated a new interest in missions to Uranus. Traditional mission design methods can be computationally expensive and are not necessarily well suited to the multiple gravity assist problem. This paper proposes a new mission design technique highlighted with a nominal design to satisfy the decadal survey. This new technique utilizes a combination of simulated annealing and genetic algorithms to conduct a trajectory search. Simulated annealing is a relatively new global optimization technique targeted at solving integer value problems such as the multiple gravity assists problem. The technique presented is compared against other common techniques and other proposed mission designs in the literature.

ISRU Mission Design Optimizer - Project on Hold

This project looks at general mission design for a mission or set of missions planning to use in-space refueling or ISRU. This looks at the cost of producing fuel at different locations (moon, mars, asteroid) and where to best store that fuel. The problem is set up using sources (where fuel is produced/stored) and sinks (where fuel is used) which are defined by the mission architecture. The cost to move from each source to each sink is calculated to find all of the possible options for how to utilize different fuel sources and assign them some kind of standard value. The main work of this project is to frame this as an optimization problem and develop a cost function to minimize some overall cost associated with the fuel used for a certain mission. A method such as this can be used to find the best locations for fuel to be positioned for a given mission concept or to plan out and size fuel refineries on different bodies given some long-term mission plans.