Abstract: The technology described here relates to LTA vehicle launch configuration and in-flight optimization. A method for automated ballast dropping by an LTA vehicle in flight may include receiving, by an in-flight ballast model, an initial lift gas fill amount and an initial ballast amount, generating altitude ranges based on a remaining lift gas amount and a current system mass of the LTA vehicle to determine whether the remaining lift gas amount is within a ballast drop lift gas range, determining whether a convergence criterion for the remaining lift gas amount is met, the convergence criterion indicating a convergence between a remaining lift gas estimate and a remaining lift gas model, determining that dropping a ballast increment will not decrease an overall ballast amount below a target ballast amount corresponding to the remaining lift gas amount, and causing the LTA vehicle to drop the ballast increment.