HEIMDALL is an expert-system code designed to aid quick — but reasonably detailed — examinations of complete HPM weapons.
Starship Propulsion Technologies vs. Speed (v/c).Sail Starships can reach close to the speed of light and will develop from solar sails. Ramjets depend on high density of interstellar hydrogen for fuel, but we’re in a low-density volume. Nuclear fission rockets were developed decades ago, but not used. We don’t yet know how to build fusion and antimatter rockets. Chemical and ion rockets can’t reach interstellar speeds.