The study of explosive astrophysical transients touches on a variety of questions including the origin of the chemical elements, the formation of neutron stars and black holes, the generation of gravitational waves, and the dynamics of the interstellar medium. At ORNL, we model supernovae—both core-collapse and thermonuclear types—using extreme-scale computational resources. These models are inherently multi-scale and multi-physics, and have required increasing amounts of computational power as our understanding has matured. I will describe some of our current projects, including our effort to build a new application code capable of taking advantage of exascale platforms. *PDH credit available for $5 Knoxville, Tennessee, United States