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Linda Spilker

Photo of Linda Spilker


4800 Oak Grove Drive
M/S 183-400

Pasadena, CA 91109





Curriculum Vitae:

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Member of:

Science Division

Research Fellow


Dr. Linda J. Spilker is a JPL Fellow, Senior Research Scientist and planetary scientist at NASA’s Jet Propulsion Laboratory who has participated in NASA and international planetary missions for over 45 years. She is currently serving as the Voyager Project Scientist. Her mission roles have grown to encompass mission leadership as well as design, planning, operation and scientific data analysis. Prior to Voyager, Spilker was the Cassini Project Scientist, leading a team of over 300 international scientists to maximize the scientific return of the Cassini mission within cost and schedule. She worked in a science role on the Cassini project for 30 years, and was a Co-I with the Cassini Composite Infrared Spectrometer (CIRS) team. She led the CIRS ring team focusing on thermal infrared studies and modeling of Saturn’s rings to address questions of the rings’ origin and evolution. She led the science preparation of two Cassini Senior Review Proposals, in 2012 and 2014, both of which received Excellent ratings. She also participated in a 2023 Voyager Senior Review proposal.

Prior to Cassini, Spilker previously worked on Voyager for 12 years, as the Experiment Representative (science liaison to the project) with the Infrared Radiometer and Spectrometer (IRIS) team and as a science associate with the Photopolarimeter Team. Prior to that she was a research assistant (as L. Horn) in the Geology Department at Caltech studying the lead and bismuth distribution in meteorite samples, with a focus on carbonaceous chondrites and early solar system history and formation.

Spilker is a member of the Outer Planets Assessment Group (OPAG) Steering Committee after serving for five years as OPAG Vice-Chair, then Co-Chair. She was previously the Chair for the Division for Planetary Sciences (DPS). She was an author or coauthor on a number of white papers for the 2023 Planetary Science and Astrobiology Decadal Survey. She has also participated on the Advisory Council for Planetary Data System Ring-Moon Systems Node since 1990, providing input on archiving data from Cassini and other planetary missions.

Over the years Spilker has mentored numerous postdocs, graduate students and summer students as well as young scientists at JPL and other institutions. She is committed to transferring knowledge and training future generations.


  • B.A. in Physics, California State University, Fullerton (1977)
  • M.S. in Physics, California State University, Los Angeles (1983)
  • Ph.D. in (summa cum laude), Geophysics and Space Physics UCLA (1992)

Professional Experience

Jet Propulsion Laboratory (1977-present)

Project Work

  • Voyager Project Scientist (2022 – Present)
  • Voyager Deputy Project Scientist (2020 – 2022)
  • Cassini Project Scientist (2010 – 2019)
  • Enceladus Life Finder Proposal Project Scientist, Discovery and NF (2014 – 2018)
  • Cassini Deputy Project Scientist (1997 – 2010)
  • Cassini Mission Scientist (1990 – 1997)
  • Cassini CIRS Investigation Scientist (1990 – 1992)
  • Cassini Assistant Study Scientist (1988 – 1990)
  • Hermes Discovery Mission Proposal Deputy Principal Investigator (1993 – 1998)
  • Voyager IRIS Experiment Representative (1979 – 1990)
  • Voyager IRIS Assistant Experiment Representative (1977 – 1979)

Science Work

  • Cassini Composite Infrared Spectrometer (CIRS) Co-Investigator (1990 – 2019)
  • Visiting Scientist at University of Paris 7 (2001, 2010)
  • Principal Investigator, Cassini Data Analysis Program (CDAP) (2009 – 2012 )
  • Principal Investigator for Ring Structure and Dynamics, OPR (2004 – 2006)
  • Principal Investigator for Planetary Ring Studies in PG&G (1993 – 1997, 1999 – 2002)
  • Co-Investigator on Coherent backscatter opposition effect in PG&G (1990 – 1997)
  • Co-Investigator on compositional mapping of Io using mutual satellite occultations (1990 – 1991)
  • Voyager Photopolarimeter (PPS) Science Associate (1984 – 1990)
  • Voyager Infrared Radiometer & Spectrometer (IRIS) Science Associate (1988 – 1990)

Community Service

  • Chair, Division of Planetary Sciences, American Astronomical Society (2018-2019)
  • Guest editor, Icarus, for Cassini special issue (2018-2020)
  • Guest editor, Geophysical Research Letters (2018-2019)
  • Co-Chair, Outer Planets Assessment Group (OPAG) (2017-2022)
  • Chair, COSPAR Commission B5 (Outer Planets) (2016-2020)

  • Scientific Organizing Committee, Division of Planetary Science, Pasadena, CA (2016, 2006)
  • Outer Planets Assessment Group (OPAG) Steering Committee (2008 – Present)
  • JPL Advisory Council for Women (2001-2004)
  • Planetary Science Data Steering Group (1991-1994)
  • Advisory Council for Planetary Data System Ring Node(1990 – Present)
  • JPL Speaker’s Bureau (1980 – Present)

Research Interests

  • Thermal infrared studies of Saturn's rings to address questions of ring evolution
  • Numerical modeling of gravitational waves and wakes in Saturn's rings to estimate local surface mass density and ring mass
  • Acquisition and interpretation of Cassini Composite Infrared Spectrometer (CIRS) data to determine ring dynamics from thermal behavior as a function of solar and ring geometry

Selected Awards

  • JPL Voyager Award (2020)
  • NASA Outstanding Public Leadership Medal, Cassini Project Scientist (2018)
  • Cal State University Fullerton Alumna of the Year Award (2018)
  • JPL Magellan Award (2018)
  • The Women’s International Film and Television Showcase (The WIFTS) Foundation - Visionary Award (2017)
  • JPL Voyager Award (2016)
  • JPL Magellan Award (2014)
  • NASA Exceptional Service Medal, Cassini Project Scientist and Deputy Project Scientist (2013)
  • NASA Exceptional Service Medal, Voyager IRIS Neptune Encounter (1990)
  • NASA Group Achievement Awards (15) 2002-2018
    • Cassini Jupiter Flyby Team (2000)
    • Cassini CIRS Team (1998)
    • Cassini Public Outreach (1998)
    • Voyager Photopolarimeter Science (1987)
    • Seven (7) NASA Group Achievement Awards for Voyager Mission (1982-1989)
  • Distinguished Alumna Award from California State University, Fullerton (2005)
  • Hall of Fame Award, Placentia-Yorba Linda Unified School District (1999)
  • ESA Award for contribution to Huygens Probe (1997)
  • Distinguished Alumna Award for Natural & Social Sciences from California State University at Los Angeles (1996)
  • California State University Fullerton Dept. of Physics Faculty Prize for Scholarship (1977)

Selected Publications

1. Ip, W.-H., Spilker, L., and Lebreton, J.-P. 2023. History of Titan Exploration, In R. Lopes (Eds.), Titan After Cassini-Huygens: COSPAR, accepted.

2. Spilker, L., Buffington, B., Smith, J., Strange, N., Buratti, B., Ray, T., Bellerose, J., Maize, E., Webster, J. 2023. The Road to the Grand Finale. In K. Baines, M. Flasar, N. Krupp, & T. Stallard (Eds.), Saturn: The Grand Finale (Cambridge Planetary Science), Cambridge: Cambridge University Press, accepted.

3. Lasue, J., … Spilker, L., 2023. Chapter 4, “From Planetary Exploration Goals to Technology Requirements”, Planetary Exploration: Horizons 2061, A Long-Term Perspective for Planetary Exploration, Elsevier, pp.177-248,

4. Royer, A. Hendrix, J. Elliott, L. Esposito, C. Howett, L. Spilker. Helene’s surface properties from photometric multi-wavelength analysis, 2023. Icarus, Vol. 392, 177-248.

5. Probst, A., Spilker, L., Hofstadter, M., Spilker, T., Atkinson, D., Probst, L., Mousis, O, and Simon, A. 2022. VPIRE: A tool aiding the design for entry probe missions. Planetary Science Journal (PSJ), 3, 98.

6. Rymer, A. …Spilker, L., 2021. Neptune Odyssey: A Flagship Concept for the Exploration of the Neptune–Triton System. Planetary Science Journal, 2. 184-199.

7. Cable, M. … Spilker, L., 2021. The Science Case for a Return to Enceladus. Planetary Science Journal. 2. 132-143.

8. MacKenzie, S., …Spilker, L. 2021. The Enceladus Orbilander Mission Concept: Balancing Return and Resources in the Search for Life. Planetary Science Journal, 2. 77-94.

9. Flandes, A., Garcia-Reyes, A., Spilker, L. 2020. Ray tracing modeling of Saturn’s main rings. Icarus, Vol. 354, 114063,

10. Spilker, L., Cassini-Huygens Exploration of the Saturn system: thirteen years of discovery. 2019. Science, Vol. 364, Issue 6445, 1046-1051, DOI: 10.1126/science.aat3760.

11. Spilker, L. J., 2019. Cassini's Final Year at Saturn: Science Highlights and Discoveries. Geophysical Research Letters, 46, 11, 5754-5758.

12. Tiscareno, M., Nicholson, P., Cuzzi, J., Spilker, L., … 2019. Remote sensing of Saturn’s rings during Cassini’s ring-grazing orbits and Grand Finale. Science, 364, Issue 6445, DOI: 10.1126/science.aau1017

13. Flandes, A., Garcia, A., Spilker, L., Deau., E. 2018. Ray-tracing thermal modeling of Saturn’s main rings. Icarus, 312, 157-171, (2018).

14. Spilker, L. The Scientific Achievements of the Cassini-Huygens mission. 2018. Serendipities in the Solar System and Beyond. ASP Conference Series, Vol. 513, proceedings of a conference held 10-13 July 2017 at National Central University, Taiwan. Edited by Chung-Ming Ko, Chan-Kao Chang, and Po-Chieh Yu. San Francisco: Astronomical Society of the Pacific, 131- 150.

15. Dougherty, M. and Spilker, L. 2018. Review of Saturn’s icy moons following the Cassini mission. IOP Reports on Progress in Physics, Vol. 81, No. 6, 1-20. DOI: 10.1088/1361-6633/aabdfb

16. Spilker, L., Ferrari, C., Altobello, N., Pilorz, S., & Morishima, R. 2018. Thermal Properties of Rings and Ring Particles. In M. Tiscareno & C. Muray (Eds.), Planetary Ring Systems: Properties, Structure, and Evolution (Cambridge Planetary Science, pp. 399-433). Cambridge: Cambridge University Press. Doi: 10.1017/9781316286791.015

17. Morishima, R.; Spilker, L.; Brooks, S.; Deau, E.; Pilorz, S. 2016. Incomplete cooling down of Saturn's A ring at solar equinox: Implication for seasonal thermal inertia and internal structure of ring particles. Icarus, Volume 279, 2-19. Doi: 10.1016/j.icarus.2015.06.025

18. Altobelli, N.; Lopez-Paz, D,; Pilorz, S.; Spilker, L..; Morishima, R.; Brooks, S.; Leyrat, C.; Deau, E.; Edgington, S.; Flandes, A. 2014. Two numerical models designed to reproduce Saturn ring temperatures as measured by Cassini-CIRS. 2014. Icarus, Volume 238, 205-220.

19. Morishima, R., Spilker, L., Turner, N., 2014. Azimuthal temperature modulations of Saturn's A ring caused by self-gravity wakes. Icarus 228, 247-229.

20. Spilker, L., C. Ferrari, R. Morishima. Saturn’s ring temperatures at equinox. 2013, Icarus 226, 316-322.

21. Morishima, R., Spilker, L., Edgington, S. Regolith grain sizes of Saturn's rings inferred from Cassini-CIRS far-infrared spectra. Icarus, Volume 222, Issue 2, 888-899.

22. Morishima, R., Spilker, L., Ohtsuki, Keiji. A multilayer model for thermal infrared emission of Saturn's rings III: Thermal inertia inferred from Cassini CIRS. 2011, Icarus, Volume 215, Issue 1, 107-127.

23. Morishima, R., L. Spilker, H. Salo, K. Ohtsuki, N. Altobelli, S. Pilorz. A multilayer model for thermal infrared emission of Saturn's rings II: Albedo, spins, and vertical mixing of rings. 2010, Icarus, Volume 210, Issue 1, 330-345.

24. Flandes, A., Spilker, L., R. Morishima, S. Pilorz, C. Leyrat, N. Altobelli, S. Brooks, S. Edgington, Brightness properties of Saturn's rings with decreasing solar elevation, 2010, Planetary and Space Science, Volume 58, Issue 13, 1758 - 1765.

25. Cuzzi, J.N., J. A. Burns, S. Charnoz, R. N. Clark, J. E. Colwell, L. Dones, L. W. Esposito, G. Filacchione, R. G. French, M. M. Hedman, S. Kempf, E. A. Marouf, C. D. Murray, P. D. Nicholson, C. C. Porco, J. Schmidt, M. R. Showalter, L. Spilker, J. N. Spitale, R. Srama, M. Sremčević, M. S. Tiscareno, J. Weiss. An Evolving View of Saturn's Dynamic Rings. 2010. Science, Volume 327, 1470 -

26. Cuzzi, J, R. Clark, G. Filacchione, R. French, R. Johnson, E. Marouf, Spilker. Ring Particle Composition and Size Distribution, 2009, in M. Dougherty, L. Esposito and T. Krimigis, eds., Saturn from Cassini-Huygens, Dordrecht, Springer, ISBN 978-1-4020-9216-9, 459 - 509.

27. Altobelli, N., L. Spilker, C. Leyrat, S. Pilorz, S. Edgington, A. Flandes, Thermal phase curves observed in Saturn's main rings by Cassini CIRS. Vol. 36, L10105, 2009.

28. Ferrari, C., Brooks S., Edgington S., Leyrat C., Pilorz S. and Spilker L., Structure of self-gravity wakes in Saturn's A ring as measured by Cassini CIRS, 2009, Icarus, Volume 199, Issue 1, 145-153.

29. Spilker, L. Saturn Revolution. 2008. Astronomy 36, No. 10, 34 - 39.

30. Altobelli, N., L. Spilker, C. Leyrat, S. Pilorz, 2008. Thermal observations of Saturn's main rings by Cassini CIRS: Phase, emission and solar elevation dependence, Planetary and Space Science, 56, 134-146.

31. Leyrat, C., L. Spilker, N. Altobelli, S. Pilorz, C. Ferrari, 2008. Infrared observations of Saturn's rings by Cassini CIRS : Phase angle and local time dependence, Planetary and Space Science, 56 (2008) 117-133.

32. Altobelli, N., L. Spilker, S. Pilorz, S. Brooks, S. Edgington, B. Wallis, M. Flasar, 2007. C ring fine structures revealed in the thermal infrared, Icarus, 191, 691-701.

33. Spilker, L. J., S. H. Pilorz, B. D. Wallis, J. C. Pearl, J. N. Cuzzi, S. M. Brooks, N. Altobelli, S. G. Edgington, M. Showalter, F. M. Flasar, C. Ferrari, C. Leyrat, 2006. Cassini Thermal Observations of Saturn's main rings: Implications for particle rotation and vertical mixing, Planetary and Space Science, 54, Issue 12, 1167-1176.

34. Spilker, L., S. Pilorz, B. Wallis, S. Edgington, S. Brooks, J. Pearl, J., F. Flasar, 2005. Cassini CIRS Observations of a Roll-off in Saturn Ring Spectra at Submillimeter Wavelengths. Earth, Moon and Planets, Volume 96, Issue 3-4, 149-163.

35. Spilker, L.J., S. Pilorz, A.L. Lane, R.M. Nelson B. Pollard, and C. T. Russell. 2004. Saturn A ring surface mass densities from spiral density wave dispersion behavior. Icarus 171, 372 - 390.