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.
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.