Gary Zank is a space physicist who works on the physics of the solar wind, especially its interaction with the local interstellar medium, the acceleration and transport of energetic particles, turbulence, and shock waves. Gary Zank’s research interests extend across space physics, plasma astrophysics, and plasma physics. Although his research is related primarily to theory, modeling, and simulations, Zank is involved in numerous experimental and observational programs. Some areas of research include the interaction of the solar wind with the partially ionized interstellar medium. Zank and colleagues introduced models that include the coupling of the partially ionized interstellar gas with heliospheric plasma, which led to the prediction and subsequent observation of the so-called hydrogen-wall. Related work using Lyman-alpha absorption measurements led to the discovery of an extra-solar hydrogen-wall at alpha-Cen, and the discovery of a solar-like stellar wind from another solar-like star (alpha-Cen). Work on interstellar pickup ions showed that pickup ion reflection is the primary dissipation mechanism at the heliospheric termination shock, a result that was confirmed by Voyager 2 12 years later. Zank and colleagues explored turbulence throughout the heliosphere, developing models of so-called nearly incompressible magnetohydrodynamics as well as transport models for turbulence. This work underpins the scattering of charged particles and the heating and driving of the corona and solar wind throughout the heliosphere, making the broader implications of this work substantial. Zank has led the development of a quantitative understanding and modeling of gradual solar energetic particle events, energetic particles accelerated by shock waves driven by coronal mass ejections.