Publications

Journals

D. Conte, A.M.S. Goodyear, J. A. Reiter, G. Paik, G. He, M. Nayyar, M.T. Shaw, J.U. Small, and J.M. Everett, “GTOC 9: Results from the Astrodynamics Research Group of Penn State,” Acta Futura (under review)

Myers, P.L., and D.B. Spencer, “Application of a Multi-Objective Evolutionary Algorithm to the Spacecraft Stationkeeping Problem”, accepted for publication, Acta Astronautica, 2016

Reiter, J.A., D.B. Spencer, “Technique to Optimize for Engine Shutoff Constraints in Electric-Propulsion Trajectories“, Journal of Spacecraft and Rockets, Vol. 53, No. 4 (2016), pp. 782-786.

Spencer, D.B., and B.S. Shank, “Trade Space Visualization Applied to Lambert’s Problem for Elliptical Insertion Orbits”, Acta Astronautica, Vol. 122, May-June 2016, pp. 243-257, 2016.

Abraham, A.J., D.B. Spencer, and T.J. Hart, “Early Mission Design of Transfers to Halo Orbits via Particle Swarm Optimization”, accepted for publication, Journal of the Astronautical Sciences, 2016

Paul, M.V., D.B. Spencer, S.E. Lego, and J.P. Muncks, “The Penn State Lunar Lion: A University Mission to Explore the Moon”, Acta Astronautica, Vol. 96, March-April 2014, pp. 65-77, 2014

Williams, P.S., D.B. Spencer, and R.S. Erwin, “Coupling of Estimation and Sensor Tasking Applied to Satellite Tracking”, Journal of Guidance, Control, and Dynamics, Vol. 36, No. 4 pp. 993-1007, DOI: 10.2514/1.59361, 2013

Kim, J-S, J.V. Urbina, T.J. Kane and D.B. Spencer, “Improvement of TIE-GCM thermospheric density predictions via incorporation of helium data from NRLMSISE-00”, Journal of Atmospheric and Solar-Terrestrial Physics, DOI 10.1016/j.jastp.2011.10.018, 2011.

Scott, C.J., and D.B. Spencer, “Calculating Transfer Families to Periodic Distant Retrograde Orbits Using Differential Correction,” Journal of Guidance, Control and Dynamics, Vol. 33, No. 5, pp. 1592-1605, 2010.

Jordan, D.D., D.B. Spencer, T.W. Simpson, M.A. Yukish and G.M. Stump, “Optimal Continuous-Thrust Trajectories via Visual Trade Space Exploration,” The Journal of the Astronautical Sciences, Vol. 57, No. 4, pp. 755–766, 2010.

Kang, B-N., D.B. Spencer, S. Tang and D.D. Jordan, “Optimal Periodic Cruise Trajectories via a Two Level Optimization Method”, Journal of Spacecraft and Rockets, Vol. 47, No. 4, pp. 597-613, DOI: 10.2514/1.47365, 2010.

Benavides, J.C., and D.B. Spencer, “The four-body linear equations of planar relative motion”, Acta Astronautica, Vol. 22, Issue 1, pp. 285-300, 2010.

Binz, C., D.B. Spencer, D.A. Levin, and T.W. Simpson, “Designing for the Space Environment via Trade Space Exploration”, Journal of Spacecraft and Rockets, Vol. 47, No. 6, pp. 1070-1073, 2010

Scott, C.J., and D.B. Spencer, “Transfers to Sticky Distant Retrograde Orbits”, Journal of Guidance, Control and Dynamics, Vol. 33, No. 6, pp. 1940-1946, 2010.

Ferringer, M.P., D.B. Spencer, D.B., and P. Reed, “Many-objective reconfiguration of operational satellite constellations with the Large-Cluster Epsilon Non-dominated Sorting Genetic Algorithm-II”, IEEE Congress on Evolutionary Computation, 2009; CEC ‘09. Publication Date: 18-21 May 2009, pp. 340-349, DOI: 10.1109/CEC.2009.4982967.

Kim, J. S., D. B. Spencer, T. J. Kane, and J. Urbina, “Thermospheric density model blending techniques: Bridging the gap between satellites and sounding rockets”, Radio Science, 44, RS0A22, DOI:10.1029/2008RS004069, 2009.

Hur, P.-S., Melton, R.G., and Spencer, D.B., “Meeting Science Requirements for Attitude Determination and Control in a Low-Power, Spinning Nanosatellite, Journal of Aerospace Engineering, Sciences and Applications, Vol. 1, No. 1, pp. 25-33, 2008.

Mathew, A., and D.B. Spencer, “Incorporating Cooperative Learning Activities into Traditional Aerospace Engineering Curricula”, Vol. 17, No. 3, pp. 25-38, The Journal of Aviation/Aerospace Education and Research, 2008

Bessette, C.R., and D.B. Spencer, “Performance Comparison of Stochastic Search Algorithms on the Interplanetary Gravity Assist Trajectory Problem”, Journal of Spacecraft and Rockets, Vol. 44, No. 3, pp. 722-724, 2007.

Kobrick, R.L, and D.B. Spencer, “Optimizing Trajectories for Suborbital Human Spaceflight”, Journal of Spacecraft and Rockets, Vol. 44, No. 2, pp. 460-463, 2007.

Wissler, M.A., D.B. Spencer, and R.G. Melton, “Coast-Arc Orbit Stability During SpiralDown Trajectories about Irregularly Shaped Body”, Journal of Spacecraft and Rockets, Vol. 44, No. 1, pp. 254-263, 2007.

Scott, C.J., and D.B. Spencer, “Optimal Reconfiguration of Satellites in Formation”, Journal of Spacecraft and Rockets, Vol. 44, No. 1, pp. 230-239, 2007.

Bilén, S.G., C.R. Philbrick, T.F. Wheeler, J.D. Mathews, R.G. Melton, and D.B. Spencer, “An Overview of Space Science and Engineering Education at Penn State”, Aerospace and Electronic Systems Magazine, IEEE, Vol. 21, Issue 7, pp. S23-S27, 2006.

Ferringer, M.P. and D.B. Spencer, “Satellite Constellation Design Tradeoffs Using Multiple-Objective Evolutionary Computation”, Journal of Spacecraft and Rockets, Vol. 43, No. 6, pp. 1404-1411, 2006.

Chadwick, W.J. III, D.B. Spencer, and R.G. Melton, “Geometric Visibility of Ground Sites for Beacon/Relays on the Martian Moons”, Journal of Spacecraft and Rockets, Vol. 43, No. 1, pp. 228-230, 2006.

Spencer, D.B., R.G. Melton, and S.G. Chianese, “Selecting Projects for a Capstone Spacecraft Design Course from Real World Solicitations”, Journal of Aviation/Aerospace Education and Research, Vol. 16, No. 1, pp. 27-40, 2006.

Igarashi, J. and D.B. Spencer, “Optimal Continuous Thrust Orbit Transfer Using Evolutionary Algorithms,” Journal of Guidance, Control and Dynamics, Vol. 28, No. 3, pp. 547-549, 2005.

Yamato, H., and D.B. Spencer, “Orbit Transfer via Tube Jumping in Planar Restricted Problems of Four Bodies”, Journal of Spacecraft and Rockets, Vol. 42, No. 2, pp. 321-328, 2005.

Yamato, H., and D.B. Spencer, “Transit-Orbit Search for Planar Restricted Three-Body Problems with Perturbation”, Journal of Guidance, Control and Dynamics, Vol. 27, No. 6, pp. 1035-1045, 2004.

Faulds, A.L., and D.B. Spencer, “Satellite Close Approach Filtering Using Genetic Algorithms,” Journal of Spacecraft and Rockets, Vol. 40, No. 2, pp. 248-252, 2003.

Kim, Y.H., and D.B. Spencer, “Optimal Orbital Rendezvous Using Genetic Algorithms, Journal of Spacecraft and Rockets, Vol. 39, No. 6, pp. 859-865, 2002.

Herman, A.E., and D.B. Spencer, “Optimal, Low-Thrust Earth-Orbit Transfers Using Higher-Order Collocation Methods”, Journal of Guidance, Control, and Dynamics, Vol. 25, No. 1, pp. 40-47, 2002.

Cichan, T., R.G. Melton, and D.B. Spencer, “Control Laws for Minimum Orbital Changes – The Satellite Retrieval Problem”, Journal of Guidance, Control, and Dynamics, Vol. 24, No. 5, pp. 1231-1233, 2001.

Spencer, D.B., K.K. Luu, W.S. Campbell, M.E. Sorge, A.B. Jenkin, “Orbital Debris Hazard Assessment Methodologies for Satellite Constellations”, Journal of Spacecraft and Rockets, Vol. 38, No. 1, pp. 120-125, 2001.

 

Conference Proceedings and Presentations

Reiter, J.A., Goodyear, A.M.S., Conte, D., and J.M Everett, “FEASIBILITY OF LOW THRUST TRAJECTORY OPTIMIZATION APPLICATIONS TO DEBRIS REMOVAL MISSION DESIGN”, AAS 17-701, AAS/AIAA Astrodynamics Specialist Conference, Stevenson, WA, August 20-24, 2017.

Reiter, J.A., Conte D., Goodyear, A.M.A., Paik, G., He, G., Scarcella, P.C., Nayyar, M., M.J. Shaw, “THE ASTRODYNAMICS RESEARCH GROUP OF PENN STATE (ARGOPS) SOLUTION TO THE 2017 ASTRODYNAMICS SPECIALIST CONFERENCE STUDENT COMPETITION”, AAS 17-621, AAS/AIAA Astrodynamics Specialist Conference, Stevenson, WA, August 20-24, 2017.

Nayyar, M., and D.B. Spencer, “Using Particle Swarm Optimization for Earth-Return Trajectories from Libration Point Orbits”, AAS 17-410, AAS/AIAA Space Flight Mechanics Meeting, San Antonio, TX, February 5-9, 2017.

Bolden, M., P. Schumacher, D. Spencer, I. Hussein, M. Wilkins and C. Roscoe, “Computer Vision and Computational Intelligence for Real-Time Multi-Modal Space Domain Awareness”, AAS 17-449, AAS/AIAA Space Flight Mechanics Meeting, San Antonio, TX, February 5-9, 2017.

Kuppa, K, and D.B. Spencer, “Long-Term Orbit Propagation Using Symplectic Integration Algorithms”, IAC-16 C1.6.3, 67th International Astronautical Congress, Guadalajara, Mexico, September 26-30, 2016.

Reiter, J.A., and D.B. Spencer, “Trading Spacecraft Fuel Use and Mission Performance to Determine the Optimal Collision Probability in Emergency Collision Avoidance Scenarios”, IAC-16 A6.7.5, 67th International Astronautical Congress, Guadalajara, Mexico, September 26-30, 2016.

Conte, D., and D.B. Spencer, “Preliminary Study on Relative Motion and Rendezvous Between Spacecraft in the Restricted Three-Body Problem”, AAS 16-369, AAS/AIAA Space Flight Mechanics Meeting, Napa, CA, February 14-18, 2016.

Reiter, J.A., and D.B. Spencer, “An Analytical Solution to Quick-Response Collision Avoidance Maneuvers in Low Earth Orbit”, AAS 16-366, AAS/AIAA Space Flight Mechanics Meeting, Napa, CA, February 14-18, 2016.

Conte, D., and D.B. Spencer, “Targeting the Martian Moons via Direct Insertion into Mars’ Orbit”, AAS 15-580, AAS/AIAA Astrodynamics Conference, Vail, CO, August 9-13, 2015.

Conte, D., M. Di Carlo, K. Ho, D.B. Spencer, and M. Vasile, “Earth-Mars Transfers Through Moon Distant Retrograde Orbit”, AAS 15-588, AAS/AIAA Astrodynamics Conference, Vail, CO, August 9-13, 2015.

Goodyear, A.M.S., and D.B. Spencer, “Optimal Low-Thrust Geostationary Transfer Orbit Using Legendre-Gauss-Radau Collocation”, AAS 15-766, AAS/AIAA Astrodynamics Conference, Vail, CO, August 9-13, 2015

Policelli, M.J., and D.B. Spencer, “Vertical Takeoff Vertical Landing Spacecraft Trajectory Optimization Via Direct Collocation and Nonlinear Programming”, AAS 15- 354, AAS/AIAA Space Flight Mechanics Meeting, Williamsburg, VA, January 11-15, 2015.

Reiter, J.A., A.K. Nicholas, and D.B. Spencer, “Optimization of Many-Revolution, Electric-Propulsion Trajectories with Engine Shutoff Constraints”, AAS 15-237, AAS/AIAA Space Flight Mechanics Meeting, Williamsburg, VA, January 11-15, 2015.

Myers, P.L., and D.B. Spencer, “Application of a Multi-Objective Evolutionary Algorithm to the Spacecraft Stationkeeping Problem”, IAC-14-C1.8.7, 65th International Astronautical Congress, Toronto, Canada, September 29-October 3, 2014.

DiGirolamo. L.J., A.H. Hoskins, K.A. Hacker and D.B. Spencer, “A Hybrid Motion Planning Algorithm for Safe and Efficient Close Proximity, Autonomous Spacecraft Missions”, AIAA 2014-4130, AIAA/AAS Astrodynamics Specialists Conference, San Diego, CA, August 4-7. 2014.

Abraham, A.J., D.B. Spencer, and T.J. Hart, “Particle Swarm Optimization of 2-Manuver, Impulsive Transfers from LEO to Lagrange Point Orbits”, 24th International Symposium on Space Flight Dynamics, Laurel, MD, May 2014.

Abraham, A.J., D.B. Spencer, and T.J. Hart, “Preliminary 2-D Optimization of LowThrust, Geocentric-to-Halo-Orbit Transfers via Particle Swarm Optimization”, AAS 14- 199, AAS/AIAA Space Flight Mechanics Meeting, Santa Fe, NM, January 26-31, 2014.

Hassa, C.L., D.B. Spencer, and S.G. Bilén, “Drag Coefficient Estimation Using Satellite Attitude and Orbit Data”, AAS 14-349, AAS/AIAA Space Flight Mechanics Meeting, Santa Fe, NM, January 26-31, 2014.

Abraham, A.J., D.B. Spencer, and T.J. Hart. “Optimization of Preliminary Low-Thrust Trajectories From GEO-Energy Orbits to Earth-Moon, L1, Lagrange Point Orbits Using Particle Swarm Optimization.” AAS 13-925, AAS/AIAA Astrodynamics Specialist Conference, Hilton Head, SC, August 2013.

Spencer, D.B. and B.S. Shank, “Preliminary Development of an Optimized Lambert Problem Solver for Targets in Elliptical Orbits”, AAS 13-222, AAS/AIAA Space Flight Mechanics Meeting, Lihue, Hawaii, February 11-14, 2013.

McKennon-Kelly, R.E., P.S. Reed, D.B. Spencer and M.P. Ferringer, “Model Diagnostics and Dynamic Emulation: Enhancing the Understanding and Impact of Complex Models in Satellite Constellation Design”, AAS 13-441 AAS/AIAA Space Flight Mechanics Meeting, Lihue, Hawaii, February 11-14, 2013.

Paul, M.V., and D.B. Spencer, “The Penn State Lunar Lion: A University Mission to Explore the Moon”, IAC-12. B4.8.5, 63rd International Astronautical Congress, Naples, Italy, October 1-5, 2012.

Williams, P.S., D.B. Spencer, R.S. Erwin, K.J. DeMars, “The Effects of Uncertainty Estimation on Dynamic Sensor Tasking”, AIAA 2012-4808, AIAA/AAS Astrodynamics Specialists Conference Minneapolis, MN, August 13-16, 2012.

Liang, K., D.B. Spencer, and J. Yuan, “Optimizing the Perilune of Lunar Landing Trajectories Using Dynamical Systems Theory”, AIAA 2012-4430, AIAA/AAS Astrodynamics Specialists Conference, Minneapolis, MN, August 13-16, 2012.

Williams, P.S., D.B. Spencer and R.S. Erwin, “Utilizing Stability Metrics to Aid in Sensor Network Management Solutions for Satellite Tracking Problems”, AAS 12–111, AAS/AIAA Space Flight Mechanics Meeting, Charleston, SC, January 29-February 2, 2012.

Williams, P.S., D.B. Spencer and R.S. Erwin “Comparison of Two Single-Step, Myopic Sensor Management Decision Processes Applied to Space Situational Awareness”, AAS 12–112, AAS/AIAA Space Flight Mechanics Meeting, Charleston, SC, January 29- February 2, 2012

Williams, P.S., D.B. Spencer, and R.S. Erwin, “Coupling of Nonlinear Estimation and Dynamic Sensor Tasking Applied to Space Situational Awareness”, AAS 11-575, AAS/AIAA Astrodynamics Specialists Conference, July 31-August 4, 2011

Polito, C.J. and D.B. Spencer, “The Probability of Asteroid-Earth Collisions by way of the Positional Uncertainty Ellipsoid”, AAS 11-409, AAS/AIAA Astrodynamics Specialists Conference, July 31-August 4, 2011.

Benavides, J.C., and D.B. Spencer, “Analytic Solutions of the N-Body Problem”, AAS 10– 186, AAS/AIAA Spaceflight Mechanics Meeting, San Diego, CA, February 14-17, 2010.

Benavides, J.C., and D.B. Spencer, “Analytic Solutions of the Two-Body Problem”, AAS 10–182, AAS/AIAA Spaceflight Mechanics Meeting, San Diego, CA, February 14-17, 2010

Ahn, Y.T., and D.B. Spencer, “Preliminary Analysis of a Spacecraft Attitude Control System Using a Shifting Mass Distribution”, IAC-09-C1.6.7, International Astronautical Congress, Daejeon, Republic of Korea, October 12-16, 2009.

Scott, C.J., and D.B. Spencer, Families of Transfer Trajectories to Distant Retrograde Orbits, Part 1: Transfers to Periodic Orbits, AAS 09-399, AAS/AIAA Astrodynamics Specialists Conference, Pittsburgh, PA, August 9-13, 2010.

Scott, C.J., and D.B. Spencer, Families of Transfer Trajectories to Distant Retrograde Orbits, Part 2: Single Impulse Transfers and Transfers to Quasi-periodic Orbits, AAS 09 – 400, AAS/AIAA Astrodynamics Specialists Conference, Pittsburgh, PA, August 9-13, 2010.

Spencer, D.B., Simpson, T.W., Yukish, M.A., and Stump, G., (2009) “Visual Steering Commands to Support Research in Trade Space Exploration”, NSF Engineering Research and Innovation Conference, Honolulu, HI, June 22-25, 2009, National Science Foundation.

Benavides, J.C., and Spencer, D.B., “The Two-Dimensional Linearized Equations of Perturbed Relative Motion”, AAS 09-190, AAS/AIAA Spaceflight Mechanics Meeting, February 9-12, 2009, Savannah, GA.

Williams, P.S., and Spencer, D.B., “Applications of Non-Linear Constrained Optimization Methods and an Evolutionary Strategy on Low-Thrust LEO to Molniya and LEO to GEO Orbit Transfers”, AAS 09-215, AAS/AIAA Spaceflight Mechanics Meeting, February 9- 12, 2009, Savannah, GA.

Jordan, D.D., Spencer, D.B., Simpson, T.W., Yukish, M.A., and Stump, G.M., “Optimal Continuous-Thrust Orbit Transfers via Trade Space Exploration”, AAS 09-218, AAS/AIAA Spaceflight Mechanics Meeting, February 9-12, 2009, Savannah, GA.

Benavides, J.C., and D.B. Spencer, “Preliminary Assessment of the Next Generation Equations of Relative Motion”, IAC-08-C1.3.5, International Astronautical Congress, Glasgow, Scotland, September, 2008.

Simpson, T.W., D.B. Spencer, M.A. Yukish, and G.M. Stump, “Visual Steering Commands and Test Problems to Support Research in Trade Space Exploration”, 12th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, AIAA 2008- 6085, Victoria, British Columbia Canada, September 2008.

Scott, C.J., and D.B. Spencer, “Stability Mapping of Distant Retrograde Orbits and Transports in the Circular Restricted Three- Body Problem”, AIAA-2008-6431, AIAA/AAS Astrodynamics Specialists Conference, Honolulu, HI, August 2008.

Kim, J-S., D.B. Spencer, T.J. Kane, and J.V. Urbina, “A Blending Technique in Thermospheric Density Modeling”, AIAA-2008-6441, AIAA/AAS Astrodynamics Specialists Conference, Honolulu, HI, August 2008.

Ferringer, M.P., D.B. Spencer, P.M Reed, R.S Clifton, and T.G Thompson, “ParetoHypervolumes for the Reconfiguration of Satellite Constellations”, AIAA-2008-6611, AIAA/AAS Astrodynamics Specialists Conference, Honolulu, HI, August 2008.

Williams, P.S. and D.B. Spencer, “Preliminary Findings Concerning Applications of NonLinear Constrained Optimization Methods on Low- Thrust Orbit Transfers”, AIAA-2008- 6618, AIAA/AAS Astrodynamics Specialists Conference, Honolulu, HI, August 2008

Benavides, J.C., and D.B. Spencer, “Orbit Phasing Analysis for Elliptical Orbits, AAS 08- 199, AAS/AIAA Space Flight Mechanics Meeting, Galveston, TX, January 2008.

Spencer, D.B., D.D. Jordan, T.W. Simpson, M.A. Yukish, and G.M. Stump, “Optimal Spacecraft Trajectories via Trade Space Exploration”, AAS 08-246, AAS/AIAA Space Flight Mechanics Meeting, Galveston, TX, January 2008.

Spencer, D. B., Simpson, T. W., and Yukish, M. A. “Trade Space Exploration Using Visual Steering and Multidimensional Data Visualization”, NSF Engineering Research and Innovation Conference, Knoxville, TN, January 7-10, 2008, National Science Foundation.

Stodgell, T.R., and D.B. Spencer, “Satellite Rendezvous Tours Using Multiobjective Evolutionary Optimization, AAS 07-382, AAS/AIAA Astrodynamics Specialists Conference, Mackinac Island, MI, August 2007.

Benavides, J.C., and D.B. Spencer, “Sun-Earth Triangular Lagrange Point Orbit Insertion and Satellite Station Keeping”, AAS 07-234, AAS/AIAA Space Flight Mechanics Meeting, Sedona, AZ, January 2007

Bessette, C.R., and D.B. Spencer, “Identifying Optimal Interplanetary Trajectories through a Genetic Approach”, AIAA 2006-6306, AIAA/AAS Astrodynamics Specialists Conference, Keystone, CO, August 2006.

O’Malley, J.R., and D.B. Spencer, “Formation Flight Control for Modeling Interferometric Aperture Planes”, AIAA 2006-6017, AIAA/AAS Astrodynamics Specialists Conference, Keystone, CO, August 2006.

Bessette, C.R. and D.B. Spencer, “Optimal Space Trajectory Design: A Heuristic-Based Approach”, AAS 06-197, AAS/AIAA Space Flight Mechanics Meeting, Tampa, FL, January 2006.

Kobrick, R.L. and D.B. Spencer, “Optimizing Trajectories for Suborbital Human Spaceflight”, AAS 06-199, AAS/AIAA Space Flight Mechanics Meeting, Tampa, FL, January 2006.

Ferringer, M.P., and D.B. Spencer, “Satellite Constellation Design Optimization via Multiple-Objective Evolutionary Computation”, AAS 05-280, AAS/AIAA Astrodynamics Specialists Conference, Lake Tahoe, CA, August 2005.

Bilén, S.G., C.L. Croskey, R.G. Melton, D.B. Spencer, D.A. Levin, and M.M. Micci, “Students designing and building satellites: Penn State’s LionSat and the University Nanosat Program,” 2005 ASEE Annual Conference, Portland, Oregon, 13–15 June 2005.

Scott, C.J., and D.B. Spencer, “Optimal Bounded Low-Thrust Reconfiguration for Close Proximity Earth Orbiting Satellites,” AAS 05-101, AAS/AIAA Space Flight Mechanics Meeting, Copper Mountain, CO, January 2005.

Spencer, D.B., and F.A. Acon-Chen, “An Analytical Approach for Continuous-Thrust, LEO-Molniya Transfers,” AIAA 2004-5090, AIAA/AAS Astrodynamics Specialists Conference, Providence, RI, August 2004.

Igarashi, J., and D.B. Spencer, “Optimal Continuous Thrust Orbit Transfer Using Evolutionary Algorithms,” AIAA 2004-5085, AIAA/AAS Astrodynamics Specialists Conference, Providence, RI, August 2004.

Haeberle, D.W., D.B. Spencer, and T.A. Ely, “Interplanetary Navigation Using a Distributed Deep Space Network Architecture,” AIAA 2004-4744, AIAA/AAS Astrodynamics Specialists Conference, Providence, RI, August 2004.

Wissler, M.A., D.B. Spencer, and R.G. Melton, “Low Altitude Orbit Stability of the Dawn Spacecraft Around the Asteroid Vesta,” AIAA 2004-4861, AIAA/AAS Astrodynamics Specialists Conference, Providence, RI, August 2004.

Hur, Phill-Sun, R.G. Melton, and D.B. Spencer, “Attitude Determination and Control of a Nanosatellite Using the Geomagnetic Field Data and Sun Sensors”, AAS 04-144, AAS/AIAA Space Flight Mechanics Meeting, Maui, HI, February 2004.

Scott, C.J., and D.B. Spencer, “Coupled Effects of Initial Orbit Plane on Orbit Lifetime in the Three Body Problem”, AAS 04-290, AAS/AIAA Space Flight Mechanics Meeting, Maui, HI, February 2004.

Chadwick, W.J. III, D.B. Spencer, and R.G. Melton, “Geometric Analysis of Visibility of Mission Support Infrastructure for Phobos and Deimos”, AAS 04-135, AAS/AIAA Space Flight Mechanics Meeting, Maui, HI, February 2004.

Spencer, D.B., R.G. Melton, and S.G. Chianese, “Selecting Projects for a Capstone Spacecraft Design Course”, AAS 03-503, AAS/AIAA Astrodynamics Specialists Conference, Big Sky, MT, August 2003.

Akins, K.A., L.M. Healy, and D.B. Spencer, “Localized Atmospheric Density Model Validation Using High Eccentricity Satellite Observations”, AAS 03-628, AAS/AIAA Astrodynamics Specialists Conference, Big Sky, MT, August 2003.

Yamato, H., and D.B. Spencer, “Numerical Investigation of Perturbation Effects on Orbital Classifications in the Restricted Three-Body Problem”, AAS 03-235, AAS/AIAA Space Flight Mechanics Meeting, Ponce Puerto Rico, February 2003

Ahn, Y.T., and D.B. Spencer, “Optimal Reconfiguration of a Formation Flying Constellation”, IAC-020A.2.07, 53rd International Astronautical Congress, Houston, TX, October 2002.

Sheffler, S.E., A.M. Segerman, and D.B. Spencer, “A Comparison of Generated Ephemerides Using SpecialK with Various Atmospheric Models”, AIAA 2002-4542, AIAA/AAS Astrodynamics Specialists Conference, Monterey, CA, August 2002.

Yamato, H., and D.B. Spencer, “Trajectory Design of Spacecraft Using Invariant Manifolds,” ISTS 2002-s-16, International Symposium on Space Technology and Science, Matsue, Japan, May 2002.

Faulds, A.L., and D.B. Spencer, “Satellite Collision Analysis Using Genetic Algorithms as a Filter”, AAS 02-117, AAS/AIAA Space Flight Mechanics Meeting, San Antonio, TX, January 2002.

Spencer, D.B., and Y.H. Kim, “Optimal Orbital Rendezvous Using Genetic Algorithms”, AAS 01-477, AAS/AIAA Astrodynamics Specialists Conference, Quebec City, Canada, July-August 2001.

Spencer, D.B., and H. Yamato, “Very Long-Term Stability of Extrasolar Planets in Binary Star Systems”, American Astronomical Society Division on Dynamical Astronomy, 32nd Annual Meeting, Houston, TX, April 2001.

Spencer, D.B., and K.A. Akins, “Uncertainty Assessment for the Breakup of Satellites Due to Hypervelocity Impacts”, 3rd European Conference on Space Debris, Darmstadt Germany, March 2001.

Cooke, W.J., D.B. Spencer, B.J. Anderson, and R.M. Suggs, “Tether Survivability and Collision Avoidance: Is LEO the Right Place for Tethered Systems”, Space Technology and Applications International Forum, Albuquerque, NM , February 2001

Cichan, T., R.G. Melton, and D.B. Spencer, “Control Laws for Minimum Orbital Changes – The Satellite Retrieval Problem”, AIAA 2000-4430, AIAA/AAS Astrodynamics Specialists Conference, Denver, CO, August, 2000.

Spencer, D.B., C.B. Hogge, W.S. Campbell, M.E. Sorge, and S.R. McWaters, “Orbital Debris and the Environmental Restoration of Space: A Report to the Congressional Defense Committees”, presented at the Space Control Conference, M.I.T. Lincoln Laboratory, Lexington, MA, April 2000.

Spencer, D.B., K.K. Luu, W.S. Campbell, M.E. Sorge, and A.B. Jenkin, “Orbital Debris Hazard Assessment Methodologies for Satellite Constellations”, AAS 00-138, AAS/AIAA Spaceflight Mechanics Conference, Clearwater, FL, January 2000.

Herman, A.E., and D.B. Spencer, “Optimal, Low-Thrust LEO to GEO/MEO/HEO Trajectories”, AAS 99-408, AAS/AIAA Astrodynamics Conference, Girdwood, AK, August 1999.

Herman, A.E., V. Coverstone-Carroll, C.A. Hartman, and D.B. Spencer, “Optimal Spacecraft Trajectories via Higher Order Differential Inclusions”, AAS 99-128, AAS/AIAA Space Flight Mechanics Conference, Breckenridge, CO, February 1999.