Researchers used Lawrence Livermore National Laboratory's (LLNL) exascale supercomputer El Capitan to perform the largest fluid dynamics simulation ever — surpassing one quadrillion degrees of freedom in a single computational fluid dynamics (CFD) problem. The team focused the effort on rocket–rocket plume interactions. El Capitan is funded by the National Nuclear Security Administration's (NNSA) Advanced Simulation and Computing (ASC) program. The work — in part performed prior to the transition of the world's most powerful supercomputer to classified operations earlier this year — is led