David A. Spencer

Spencer received B.S. and M.S. degrees in aeronautics and astronautics from Purdue University in W. Lafayette, Indiana. He earned his Ph.D. from the Guggenheim School of Aerospace Engineering at the Georgia Institute of Technology, completing a dissertation on automated proximity operations using relative orbital elements.[2]

Spencer worked at NASA’s Jet Propulsion Laboratory from 1991 through 2008.[3] He served on mission design and navigation team for the TOPEX/Poseidon mission, and he was the lead mission designer for Mars Pathfinder, responsible for the design of the interplanetary transfer and the entry, descent and landing (EDL) trajectory.[4] Spencer served as the mission manager for NASA’s Mars Odyssey from 1997-2002, and Deep Impact from 2004-2005, leading the mission design and operations for the projects. He was the deputy project manager for the Phoenix Mars Lander, with a focus on EDL and surface operations. Spencer left JPL in 2008 to join the Aerospace Engineering faculty at Georgia Tech.

At Georgia Tech, Spencer founded the Center for Space Systems, and was the Co-Director of the Space Systems Design Laboratory, a multi-disciplinary research and educational organization dedicated to the design, development and operations of advanced space systems and technologies. He initiated a small satellite program at Georgia Tech, establishing facilities for satellite fabrication, testing, tracking and operations. He collaborated with students and faculty on the development of a series of small satellite missions.

Spencer served as mission manager for The Planetary Society's LightSail 1 spacecraft, leading the mission design and system engineering of the solar sail demonstration project. LightSail 1 was launched on May 20, 2015.[5] Spencer led the team through a successful solar sail deployment almost a month later, before LightSail 1 reentered Earth’s atmosphere.[6] Spencer is the project manager for a second LightSail spacecraft, LightSail 2, launched in 2019.[7] LightSail 2 was deployed into orbit by the Prox-1 spacecraft developed by Spencer and students at Georgia Tech.[8] LightSail 2 successfully demonstrated controlled solar sailing in Earth orbit. [9]

Spencer transitioned from Georgia Tech in 2016 to join the faculty of the School of Aeronautics and Astronautics at Purdue University, where he has an active research program on small satellite applications, proximity operations, and aeroassist technologies. He leads the Purdue Engineering Initiative on cislunar space, with the goal of expanding the orbital economy to encompass the cislunar environment. He is an Associate Fellow of the American Institute of Aeronautics and Astronautics, and served on the Board of Directors of the American Astronautical Society.

• JPL Award for Excellence, Mars Pathfinder Entry, Descent and Landing design, 1998.
• NASA Exceptional Achievement Medal, Mars Pathfinder mission design, 1998.
• JPL Award for Excellence, Mars Surveyor 2001 trajectory design, 1999.
• NASA Exceptional Service Medal, Mars Odyssey mission system leadership, 2003.
• Outstanding Aerospace Engineer Award, Purdue University, 2004.
• NASA Exceptional Achievement Medal, Deep Impact mission management, 2006.
• NASA Space Act Award, Entry, Descent and Landing Monte Carlo Simulation, 2007.
• NASA Exceptional Achievement Medal, Phoenix project management, 2009.
• NASA Group Achievement Award (6 times)
• Associate Fellow, American Institute of Aeronautics and Astronautics, 2010.

• Spencer, D.; Braun, R. (1997). "Mars Pathfinder Atmospheric Entry: Trajectory Design and Dispersion Analysis". Journal of Spacecraft and Rockets. 34 (2).
• Spencer, D.; Blanchard, R.; Braun, R.; Kallemeyn, P.; Peng, C-Y.; Thurman, S. "Mars Pathfinder Entry, Descent and Landing Reconstruction". Journal of Spacecraft and Rockets. 36: 357–366. doi:10.2514/2.3478.
• Spencer, D.; Tolson, R. "Aerobraking Cost and Risk Decisions". Journal of Spacecraft and Rockets. 44 (6): 1285–1293. doi:10.2514/1.24303.
• Arvidson, R.; Adams, D. Bonfiglio; Christensen, P.; Cull, S.; Golombek, M.; Guinn, J.; Guinness, E.; Heet, T.; Kirk, R.; Knudson, A.; Malin, M.; Mellon, M.; McEwen, A.; Mushkin, A.; Parker, T.; Seelos, F.; Seelos, K.; Smith, P.; Spencer, D.; Stein, T.; Tamppari, L. "Mars Exploration Program 2007 Phoenix landing site selection and characteristics". Journal of Geophysical Research-Planets. 113: E00A03.
• Spencer, D.; Adams, D.; Arvidson, R.; Bonfiglio, E.; Golombek, M.; Seelos, K. (2009). "Phoenix Landing Site Hazard Assessment and Selection". Journal of Spacecraft and Rockets. 46 (6).
• Lovell, T.A.; Spencer, D.A. (2014). "Relative Orbital Elements Formulation Based Upon the Clohessy-Wiltshire Equations". Journal of Astronautical Sciences. 61: 341–366. doi:10.1007/s40295-014-0029-6.
• Spencer, D.A. (2016). "Automated Trajectory Control Using Artificial Potential Functions to Target Relative Orbits". Journal of Guidance, Control, and Dynamics. 39: 2142–2148. doi:10.2514/1.G001487.
• Long, A.C.; Spencer, D.A. (2018). "A Scalable Drag Sail for the Deorbit of Small Satellites". Journal of Small Satellites. 7 (3).
• Renevey, S.; Spencer, D.A. "Establishment and Control of Spacecraft Formations Using Artificial Potential Functions". Acta Astronautica. 162: 314–326. doi:10.1016/j.actaastro.2019.06.024.
• Spencer, D.A.; Johnson, L.; Long, A.C. (2019). "Solar Sailing Technology Challenges". Journal of Aerospace Science and Technology. 93: 105276. doi:10.1016/j.ast.2019.07.009.