Fission thrust sail as booster for high Δv fusion based propulsion

Highlight•Concept of fissile-elements covered thrust sail is introduced.•Acts as booster for nuclear fusion based rockets.•Improves delta-v when fusion rocket efficiency is below ~30%.•Also improves acceleration then.•Acts as micrometeorite shield.

The fission thrust sail as booster for nuclear fusion-based rocket propulsion for future starships is introduced and studied. First order calculations are used together with Monte Carlo simulations to assess system performance. If a D–D fusion rocket such as e.g. considered in Project Icarus has relatively low efficiency (~30%) in converting fusion fuel to a directed exhaust, adding a fission sail is shown to be beneficial for the obtainable delta-v. In addition, this type of fission–fusion hybrid propulsion has the potential to improve acceleration and act as a micrometeorite shield.