Christine Hartzell
Associate Professor, Aerospace Engineering, University of Maryland
Monday, Feb. 19 | 9:30 a.m. | AERO 114
Abstract: The interaction of charged particles with the local plasma environment is of interest in a variety of space applications. This talk will focus on two specific applications: 1. the design of new technologies to detect orbital debris and 2. the evolution of asteroid surfaces. Small (sub-cm) orbital debris poses a serious hazard to functional spacecraft, but is very difficult detect (and impossible to track) using conventional technologies. Our simulations predict that many of these debris objects will produce solitons in the ionospheric plasma environment. We will present the characteristics of the debris that are predicted to produce solitons and the characteristics of the resulting solitons. Detection of debris-produced solitons may provide a new technique to monitor the highly uncertain sub-cm debris environment.
Our second topic concerns the removal of small particles from the surfaces of asteroids. The regolith of many small asteroids is coarse compared to other solar system bodies like the Moon. It has been hypothesized that small regolith particles may be removed from asteroids due to the interaction of the charged particles with the local plasma environment. We will present predictions of the sizes of particles that can be lofted from the asteroid Bennu and the subsequent trajectories (including escape) of those particles. We will also show experimental observations of the electrostatic lofting of clumps of regolith particles. Electrostatic lofting, combined with solar radiation pressure, may be an active loss mechanism on asteroids.
Bio: Christine Hartzell is an Associate Professor in the Department of Aerospace Engineering at the University of Maryland. Her research seeks to elucidate the fundamental physics of granular systems that will enable key space exploration technologies. She is a Participating Scientist on the Martian Moons Exploration (MMX) mission, and was involved with the OSIRIS-REx mission and the Janus mission. Asteroid 9319 was named “Hartzell” in recognition of her contributions to the field of asteroid science. Prior joining the faculty at UMD, Dr. Hartzell was a Keck Institute for Space Studies Postdoctoral Fellow at Caltech. She completed her PhD in Aerospace Engineering at the University of Colorado at Boulder and received her B.S. in Aerospace Engineering from Georgia Tech.