StageSim

StageSim is a web + desktop app for small rocketry teams to run fast, practical stage-separation and ascent “sanity checks” without needing a full CFD/6-DOF toolchain. Users input vehicle mass properties, thrust curves, separation mechanism assumptions, and basic aero coefficients (or import from OpenRocket/RASAero exports). The app runs Monte Carlo dispersions on key uncertainties (ignition delay, separation impulse, CG shift, wind layers) and outputs probability-of-success metrics: recontact risk, attitude rates at ignition, clearance margins, and expected apogee/velocity bands. It also generates a concise separation test plan checklist and a shareable report for internal reviews and range safety discussions. This is not a magic physics oracle; it’s a decision-support tool that highlights where your assumptions are fragile and where a simple ground test or sensor can de-risk the flight.