Accurate prediction of acidic deposition from solid rocket exhaust clouds is critical for assessing environmental and health impacts, yet large uncertainties remain under varying atmospheric conditions. This study developed a plume evolution model using a Lagrangian Particle Dispersion Model (LPDM) with a dedicated cloud rise component to better capture near- and far-field deposition. Validation with observed data showed good agreement. Application to SpaceX Starship launches at Boca Chica, Texas, suggests that under certain wind conditions, exhaust clouds could reach nearby residential areas. Although Starship uses LOX/LCH₄ propellants, nitric oxide (NO) formation during plume entrainment, and may still pose health risks.
