Zachary R Putnam

For More Information

• Video: Aerospace Engineering Faculty in Focus: Zachary Putnam
• Putnam Research Group Website

Education

• B.S., Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, May 2004
• M.S., Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, May 2006
• Ph.D., Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, May 2015

Academic Positions

• Assistant Professor, Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, Aug. 2015-present
• Research Engineer II, School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, Apr.-Jul. 2015

Other Professional Employment

• Member of the Technical Staff II, Charles Stark Draper Laboratory, Houston, TX and Cambridge, MA, Sep. 2006-Dec. 2009
• Senior Member of the Technical Staff, Charles Stark Draper Laboratory, Cambridge, MA, Jan.-Aug. 2010

Research Interests

• Space mission design
• Atmospheric and space flight mechanics
• Uncertainty analysis techniques for nonlinear systems
• Entry, descent, and landing systems
• Aerospace guidance, navigation, and control
• Hypersonic and space systems design

Selected Articles in Journals

• Putnam, Z. R. and Braun, R. D., "Analytic Assessment of Drag-Modulation Trajectory Control for Planetary Entry," Journal of the Astronautical Sciences, Vol. 65, No. 4 (2018), pp. 470-489. doi: 10.1007/s40295-018-0134-z
• Lorenz, C.G. and Putnam, Z.R., "Entry Trajectory Options for High Ballistic Coefficient Vehicles at Mars," Journal of Spacecraft and Rockets, Vol. 56, No. 3 (2019), pp. 811-822. doi: 10.2514/1.A34262  
• Falcone, G., Williams, J. W., Putnam, Z. R., "Assessment of Aerocapture for Orbit Insertion of Small Satellite at Mars," Journal of Spacecraft and Rockets, Vol. 56, No. 6 (2019), pp. 1689-1703. doi: 10.2514/1.A34444  
• Fawley, D. and Putnam, Z.R., "Comparison of Real-time Guidance Options for Discrete-event Drag Modulation Entry at Mars," Journal of Spacecraft and Rockets, Vol. 58, No. 4(2021), pp. 1071-1083. doi: 10.2514/1.A34796
• Williams, J., Gray, M., and Putnam, Z.R., "Six-Degree-of-Freedom Analysis of CubeSat Flight Performance in Very-Low Earth Orbits," Journal of Spacecraft and Rockets, Vol. 58, No. 4 (2021), pp. 1094-1106. doi: 10.2514/1.A34788
• Falcone, G. and Putnam, Z.R., "Energy Depletion Guidance for Aerobraking Atmospheric Passes," Journal of Guidance, Control, and Dynamics, published online Nov. 13, 2021. doi: 10.2514/1.G006171
• Lohan, K. and Putnam, Z.R., "Characterization of Candidate Solutions for X-Ray Pulsar Navigation," IEEE Transactions on Aerospace and Electronic Systems, Early Access, Feb. 2022. doi: 10.1109/TAES.2022.3152684
• Engel, D., Skolnik, N., and Putnam, Z.R., "Comparison of Flap-based and Bank-angle Steering for Mars Entry," Journal of Spacecraft and Rockets, published online, May 2022. doi: 10.2514/1.A35253
• Lohan, K. and Putnam, Z.R., "Survey of X-ray Pulsar Navigation Technology," IEEE Transactions on Aerospace and Electronic Systems, in press, accepted Feb. 2021.

Articles in Conference Proceedings

• Putnam, Z. R. and Braun, R. D., "Analytical Assessment of Drag-Modulation Trajectory Control for Planetary Entry," AAS Paper 15-748, AAS Astrodynamics Specialist Conference, Vail, CO, Aug. 2015.
• Anderson, T. R., Putnam, Z. R., and Braun, R. D., "Strategies for Landing Large Ballistic Coefficient Vehicles on Mars," AIAA Paper 2016-0021, AIAA Atmospheric Flight Mechanics Conference, San Diego, CA, Jan. 4-8, 2016.
• Putnam, Z. R. and Braun, R. D., "Review and Assessment of the Steep Lifting Entry Closed-Form Trajectory Solution," AIAA Paper 2016-0278, AIAA Atmospheric Flight Mechanics Conference, San Diego, CA, Jan. 4-8, 2016.
• Putnam, Z. R. and Braun, R. D., "Advances in Guidance, Navigation, and Control for Planetary Entry, Descent, and Landing Systems," AAS Paper 16-092, AAS Guidance and Control Conference, Breckenridge, CO, Feb. 5-10, 2016.
• Lohan, K. G. and Putnam, Z. R., "Moving-Mass Actuator System Options For Entry Vehicles with Deployable Decelerators," AAS Paper 16-373, AAS Spaceflight Mechanics Meeting, Napa, CA, Feb. 14-18, 2016.
• Lorenz, C. G. and Putnam, Z. R., "Optimal Hypersonic Trajectory Strategies for Supersonic Retropropulsion at Mars," AIAA 2017-0247, AIAA Atmospheric Flight Mechanics Conference, Grapevine, TX, Jan. 9-13, 2017.
• Lohan, K. G. and Putnam, Z. R., "Moving Mass Actuator Control for Mars Entry Vehicles," AAS Paper 17-134, AAS Guidance and Control Conference, Breckenridge, CO, Feb. 3-8, 2017.
• Sepulveda, J. and Putnam, Z. R., "An Assessment of Aerodynamic Flaps for Planetary Entry Trajectory Control," AAS Paper 17-035, AAS Guidance and Control Conference, Breckenridge, CO, Feb. 3-8, 2017.
• Zuiker, N. J., Williams, J. W., Putnam, Z. R., Levin, D.A., Ghosh, A. M., Goggin, M., Alexeenko, A., "Design of a CubeSat Mission to Investigate High-Enthalpy Nonequilibrium Flow Chemistry", AIAA 2018-1936, AIAA Aerospace Sciences Meeting, Kissimmee, FL, Jan. 8-12, 2018.
• Morgan, J., Nuwal, N., Williams, J., Putnam, Z. R., Levin, D. A., Pikus, A., Berger, A., Alexeenko, A., "Prediction of Flight Measurements of High-Enthalpy Nonequilibrium Flow from a CubeSat-Class Atmospheric Probe," AIAA 2018-1234, AIAA Aerospace Sciences Meeting, Kissimmee, FL, Jan. 8-12, 2018.
• Skolnik, N. and Putnam, Z. R., "Defining the Critical Depth of Impact Damage for Thermal Protection Systems," AIAA 2018-1481, AIAA Aerospace Sciences Meeting, Kissimmee, FL, Jan. 8-12, 2018.
• Falcone, G., Williams, J. and Putnam, Z.R., "Small Satellite Drag-Modulation Aerocapture Mission Design Options for Mars Small Satellites," AAS 18-052, AAS Guidance and Control Conference, Breckenridge, CO, Feb. 2-7, 2018.
• Wolf, A., Noyes, C., Strauss, W., Benito, J., Lobbia, M., McCann, J., Nakazono, B., Putnam, Z. R., and Lorenz, C. G., "Supersonic Retropropulsion on Mars Landers: Selected Design Trades," AAS Paper 18-486, AIAA/AAS Astrodynamics Specialist Conference, Snowbird, UT, August 19-23, 2018.
• Woffinden, D., Robinson, S., Williams, J., and Putnam, Z.R., "Linear Covariance Analysis Techniques to Generate Navigation and Sensor Requirements for the Safe and Precise Landing Integrated Capabilities Evolution (SPLICE) Project," AIAA 2019-0662, AIAA SciTech Forum, San Diego, CA, Jan. 2019.
• Zinner, E. and Putnam, Z.R., "Parking Orbit Selection for Mars Aerocapture-Entry Systems," AAS 19-463, AAS Spaceflight Mechanics Meeting, Maui, HI, Jan. 2019.
• Lohan, K. and Putnam, Z.R., "Characterization of Candidate Vehicle States for XNAV Systems," AAS 19-645, AAS Astrodynamics Specialist Conference, Portland, ME, Aug. 2019.
• Falcone, G. and Putnam, Z.R., "Aerobraking Trajectory Control Using Articulated Solar Panels ," AAS 19-682, AAS Astrodynamics Specialist Conference, Portland, ME, Aug. 2019.
• Williams, J. W., Gray, M.I., and Putnam, Z.R., "Vehicle and Mission Design Options for Very Low Earth Orbit CubeSats," AAS 19-860, AAS Astrodynamics Specialist Conference, Portland, ME, Aug. 2019.
• Williams, J.W., Woffinden, D., and Putnam, Z.R., "Mars Entry Guidance and Navigation Analysis Using Linear Covariance Analysis Techniques," AIAA 2020-0597, AIAA SciTech Forum, Orland, FL, Jan. 2020.
• Skolnik, N. and Putnam, Z.R., "Evaluation of Formulations for Self-Healing Thermal Protection System Applications ," AIAA 2020-0401, AIAA SciTech Forum, Orland, FL, Jan. 2020.
• Fawley, D. and Putnam, Z.R., "Comparison of Real-time Guidance Options for Drag-Modulation Entry at Mars ," AIAA 2020-0848, AIAA SciTech Forum, Orland, FL, Jan. 2020.
• Falcone, G. and Putnam, Z. R., "Closed-Form Trajectory Solution for Shallow, High-Altitude Atmospheric Flight," AAS 20-448, 2020 AAS Astrodynamics Specialist Conference, Remote, Aug. 2020.
• Falcone, G. and Putnam, Z. R., "Design and Development of an Aerobraking Trajectory Simulation Tool," AIAA 2021-1065, AIAA SciTech Forum, Nashville, TN, Jan. 2021. doi: 10.2514/6.2021-1065
• Engel, D., Skolnik, N., and Putnam, Z.R., "Configuration Options for Hypersonic Flaps for Mars Entry Systems," AIAA 2021-0933, AIAA SciTech Forum, Nashville, TN, Jan. 2021. doi: 10.2514/6.2021-0933
• McClary, M. and Putnam, Z. R., "Assessment of Hypersonic Separation Dynamics For Drag Modulation Systems at Mars," AIAA 2021-1063, AIAA SciTech Forum, Nashville, TN, Jan. 2021. doi: 10.2514/6.2021-1063
• Skolnik, N. and Putnam, Z.R., "Parametric Assessment of Effect of Designed-in Features on Thermal Response of TPS for Self-Healing Applications," AIAA 2021-1716, AIAA SciTech Forum, Nashville, TN, Jan. 2021. doi: 10.2514/6.2021-1716
• Engel, D., Dutta, S., and Putnam, Z.R., "Numerical Predictor-Corrector Based Guidance Scheme for Aero-Gravity Assist at Titan for Enceladus Missions," AAS 21-201, AAS Spaceflight Mechanics Meeting, Charlotte, NC, 2021.
• Hou, L., Lohan, K., and Putnam, Z.R., "Comparison and Error Modeling of Velocity-Based Initial Orbit Determination Algorithms," AAS 21-280, AAS Spaceflight Mechanics Meeting, Charlotte, NC, 2021.
• Williams, J., Brandenburg, W., Woffinden, D., and Putnam, Z.R., "Validation of Linear Covariance Techniques for Mars Entry, Descent, and Landing Guidance and Navigation Performance Analysis," AIAA 2022-0745, AIAA SciTech Forum , San Diego, CA, Jan. 2022.
• Brandenburg, W., Williams, J., Woffinden, D., and Putnam, Z.R., "Demonstration of Linear Covariance Analysis Techniques to Evaluate Entry, Descent, and Landing Guidance Algorithms, Vehicle Configurations, Analysis Techniques, and Trajectory Profiles," AIAA 2022-1215 AIAA SciTech Forum , San Diego, CA, Jan. 2022.
• Engel, D. and Putnam, Z.R., "Control of a Blunt Body Mars Entry Vehicle with Flaps Using Model Predictive Control, " AIAA 2022-1615, AIAA SciTech Forum, San Diego, CA, Jan. 2022.
• Skolnik, N. and Putnam, Z.R., "Experimental Assessment of Thermal Response of Insulating Thermal Protection Systems with Designed-in Features," AIAA 2022-2287, AIAA SciTech Forum, San Diego, CA, Jan. 2022.
• Falcone, G. and Putnam, Z.R., "Deep Reinforcement Learning for Autonomous Aerobraking Maneuver Planning and Scheduling," AIAA 2022-2497, AIAA SciTech Forum, San Diego, CA, Jan. 2022.
• Helfin, L., Zuiker, N., and Putnam, Z.R., "Linear Covariance Analysis Framework for Aerospace Vehicle Trajectory Modeling and Parametric Design," AIAA 2022-2276, AIAA SciTech Forum, San Diego, CA, Jan. 2022.
• Fawley, D., Putnam, Z.R., and D'Souza, S.N., "Assessment of Conductivity in Rarefied Flow about Mars Entry Vehicles," AIAA 2022-0825, AIAA SciTech Forum, San Diego, CA, Jan. 2022.
• Sharma, A., Adduci, A.C, Rovey, J.L., Putnam, Z.R., Lembeck, M.F., Ryan, C.N., Ma, C., Berg, S.P., “Green Ionic Liquid Multimode Monopropellant Microthruster,” AIAA 2022-1733, AIAA SciTech Forum , San Diego, CA, Jan. 2022.

Refereed Conference Papers and Presentations

• Falcone, G., Engel, D., Ryan, C.N., Rovey, J.L., Putnam, Z.R., Berg, S., Lembeck, M., "Mission Performance Assessment of Multi-mode Propulsion for Satellite Servicing Applications," IEEE Aerospace Conference, Big Sky, MT, March 2022.

Professional Societies

• American Institute of Aeronautics and Astronautics: student member (2004-2006), professional member (2006-2010), senior member (2010-present)
• AIAA Atmospheric Flight Mechanics Technical Committee: member (2015-present), awards subcommittee chair (2019-present)
• American Society for Engineering Education: student member (2012-2015), member (2015-present)
• American Astronautical Society: student member (2013-2015), member (2015-present)