Discovery III: Missions to the Outer Planets Using Inertial Confinement Fusion Propulsion

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In the future, space missions to the outer planets within our solar system that carry a human crew may be possible. This work revisits a NASA crewed spacecraft design concept Discovery II, which proposed to use a spherical torus magnetic confinement fusion reactor. The revised spacecraft Discovery III is modeled using a numerical spacecraft propulsion and mission profile code called HeliosX written in Fortran 95, but using an inertial confinement fusion engine for the same 172-ton payload mass, matching mass flow rates and exhaust velocities, achieving a mission time of 118 days for Jupiter and 212 days for Saturn. Both the inertial confinement fusion (ICF) and magnetic confinement fusion vehicles utilize expellant propellant for mass flow rate augmentation by the thermalization of injected hydrogen and thermonuclear fuel in the exhaust. Calculations are performed and the models are assessed for deviation from optimality. It is concluded that, while the ICF version is more massive, less mature technologically, and the worst performer in terms of jet efficiency, preliminary results indicate a lower fuel requirement, which may imply a technological advantage.