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. Past and current instrumentation projects include the Electric Fields and Waves (EFW) instrument on the Van Allen Probes mission (studying Earth's radiation belts), the FIELDS instrument on the Magnetospheric Multiscale mission (MMS) (studying magnetic reconnection), and the FIELDS instrument on the Parker Solar Probe mission (studying solar wind heating and acceleration). Future instrumentation projects will explore the plasma physics of Earth's ionosphere and the lunar surface.