I study plasma physics of the heliosphere, including the solar wind, planetary magnetospheres, and planetary ionospheres. Topics of particular interest include: high-frequency plasma waves, wave-particle interactions, solar wind dynamics, cosmic dust impacts on spacecraft, and spacecraft charging. To enable these studies and others, I develop scientific instrumentation for spacecraft, focusing on the measurement of electric and magnetic fields as well as on signal processing techniques and hardware.

Current instrumentation projects include the Atmospheric Electrodynamics probe for THERmal plasma (AETHER) instrument on the Geospace Dynamics Constellation, the Lunar Surface Electromagnetics Experiment (LuSEE), and the Rapid Active Plasma Sounder (RAPS) for the COUSIN sounding rocket.

Completed instrumentation projects include the FIELDS instrument on the Parker Solar Probe mission, the FIELDS instrument on the Magnetospheric Multiscale mission (MMS), and the Electric Fields and Waves (EFW) instrument on the Van Allen Probes mission.