Current Research Interests

Spaceflight mechanics / astrodynamics

Numerical methods applied to astrodynamics

Efficient software implementation (parallel computing, GPU computing)

Orbit estimation/ filtering theories/ applications

Optimal control of nonlinear systems

Third-body and manifold dynamics (low energy transfers, captures, and escapes)

Periodic orbits and general orbit stability (high-fidelity repeat ground track design, constellation design, cyclers, planetary moon trajectories)

General trajectory designs for spacecraft missions to low-Earth-orbit, Geo-stationary, the Moon, libration points, Mars, comets, asteroids, and the Jupiter and Saturn moon systems



Current Graduate Students


Kevin Bokelmann,

Etienne Pellegrini,

David Ottesen,

Ashley Biria,

Ricardo Leon Restrepo,

Robert See,

Patrick Wittick

Forrest Ward,

Tyler Mancini,

Sean Mcardle,

Chun-Yi Wu,


Graduated Students


Hatten, Noble, Space Object Translational and Rotational State Prediction and Sensitivity Calculation, December 2016

Olson, Corwin, Sequential Estimation Methods for Small Body Optical Navigation, Summer 2016

Vivek, Uncertainty Propagation and Conjunction Assessment for Resident Space Objects, Fall 2015

Demyan Lantukh, Preliminary Design of Spacecraft Trajectories for Missions to Outer Planets and Small Bodies , Summer 2013.

Nick Bradley, Initial Guess and Optimization Strategies for Multi-Body Space Trajectories with Application to Free Return Trajectories to Near-Earth Asteroids, Summer 2014.

Nitin Arora, High Performance Algorithms to Improve the Runtime Computation of Spacecraft Trajectories, Summer 2013.

Gregory Lantoine, A Methodology for Robust Optimization of Low-Thrust Trajectories in Multi-Body Environments, Fall 2010.

Kybeom Kwon, A Novel Numerical Analysis of Hall Effect Thruster and Its Application in Simultaneous Design of Thruster and Optimal Low-Thrust Trajectory, Summer 2010. (co-advised)


Etienne Pellegrini , Max Schadegg, Hemanshu Patel, Danny Browne, Josh Ross, Kevin Bokelmann, Demyan Lantukh, Nitin Arora, Danny Browne, Adam Brinckerhoff, Bala Radharamanan, Sean Blackman, Jason Yu, Cengiz Akinli (co-advised), William J. Gallagher (co-advised)


Brief Bio


R.P.R. began his professional career as a member of the Guidance, Navigation, and Control Section at NASA's Jet Propulsion Laboratory where he was involved as mission designer and orbit determination analyst for a variety of space flight projects. He also worked on proposals and advanced concepts for space missions to Earth, the Moon, Mars, comets, asteroids, and the moons around Jupiter and Saturn. He further supported internal research on developing technologies such as low-thrust trajectory optimization and science orbit design at planetary moons. From 2007-2011, RPR was on the faculty at the Georgia Institute of Technology, creating a research program focused on a variety of theoretical and applied areas in astrodynamics. R.P.R. has authored or co-authored over a hundred, conference, and other technical publications; and has been a recipient of several NASA, JPL, AIAA, AAS, and other awards.







Gravity Field Computation (global mascon models)

Gravity Field Computation (Fetch: 3D interpolation)

Fast Lambert Algorithm

F and G Stark Series (Kepler plus constant perturbation)

Shadow Model for fast low-thrust propagation

Vinti state transition matrix for relative motion




Example Orbit Movies


Resource Management for Satellite Catalogue Tracking


Titan-Enceladus Cycler


Ganymede Science Orbit (.avi) (.mpg) (.mov)


Enceladus Science Orbit (top view, 3D view)


V-infinity globe with free return locations


RTBP periodic orbit family evolution example

(credit: Martin Lara)



Other Links


Space Systems Design Lab (SSDL) at Georgia Tech

Orbit Mechanics at UT alumni pages: Drew R. Jones

Paper on Experimenting with Algorithms found on The ACM Transactions on Mathematical Software (TOMS) website:


D.S. Johnson, A Theoretician's Guide to the Experimental Analysis of Algorithms, in Proceedings of the 5th and 6th DIMACS Implementation Challenges, M. Goldwasser, D. S. Johnson, and C. C. McGeoch, Editors, American Mathematical Society, Providence, 2002.









Last updated:
December 5, 2016



Orbital Mechanics Discipline Area

research group of:
Ryan P. Russell

Associate Professor, Ph.D


Department of Aerospace Engineering and Engineering Mechanics