MEAM Seminar: “Defending the Planet: The DART Mission, and Mechanics Among the Asteroids”
September 26 at 10:00 AM - 11:30 AM
An on-orbit demonstration of asteroid deflection is a key test of our ability to defend the planet from an incoming asteroid. The recent DART (Double Asteroid Redirection Test) mission was NASA’s demonstration of kinetic impactor technology, impacting an asteroid to adjust its speed and path. The DART spacecraft impacted the asteroid Dimorphos on September 26, 2022, and was the first-ever space mission to demonstrate asteroid deflection by a kinetic impactor. We discuss the mission, and the critical role that mechanics plays in such planetary defense missions.
Most asteroids are “small” rocky bodies (they can vary in size from sub-m to several hundred km). The structure and surface topography of asteroids are determined by impact and fracture processes that occur over an immense range of timescales. Recent observations have demonstrated that many small asteroids are “rubble-piles,” collections of rocks held together by gravity. What determines this structure? We examine the disruption and breakdown of asteroids by studying the multiscale mechanics of dynamic fracture and fragmentation, coupled with computational simulations of gravitational re-accumulation. The critical mechanisms are addressed through fundamental high-strain-rate experiments, high-speed visualization, theoretical and computational modeling of failure processes, and computational simulations of asteroid damage and disruption. Our focus is on the relative roles of impact and thermal loading on the nature of near-Earth asteroids (NEAs) that may potentially impact the Earth.
Kaliat (K.T.) Ramesh
Alonzo G. Decker, Jr., Professor of Science & Engineering, Johns Hopkins University
K. T. Ramesh is the Alonzo G. Decker, Jr., Professor of Science & Engineering at Johns Hopkins University, Executive Director of the Johns Hopkins AI-X Foundry, founding Director of the Hopkins Extreme Materials Institute, and a Professor in the Departments of Mechanical Engineering, Materials Science and Engineering, and Earth & Planetary Sciences. His research interests are the broad areas of impact and failure of materials under extreme conditions, with specific interests in AI applied to materials design, protection materials, impact processes in planetary science, and impact biomechanics. He has a particular interest in the ways in which creativity can be integrated into the sciences, arts, and engineering. His work has applications in protecting people, structures, and the planet.