The U.S. Department of Energy (DOE) has awarded major computer hours on three leading supercomputers, including the world’s fastest, to a team led by C.S. Chang of the DOE’s Princeton Plasma Physics Laboratory (PPPL). The team is addressing issues that must be resolved for successful operation of ITER, the international experiment under construction in France to demonstrate the feasibility of producing fusion energy—the power that drives the sun and stars—in a magnetically controlled fusion facility called a “tokamak.”