12-04, 14:20–14:40 (Europe/Luxembourg), Banquet Room
Flyby probes are often used for a first glimpse, but robust exploration of exoplanets will inevitably require a propulsion system capable of deceleration into orbit around a nearby star and/or an exoplanet. Given the vast distances between stars, spacecraft cruise velocities of at least a few percent of the speed of light will need to be achieved. Deceleration from such velocities requires a propulsion system with particle exhaust velocities corresponding to kinetic energies of at least 1 MeV/nucleon. Conventional fission reactors are too heavy, and their architecture is incompatible with the emission of such energetic exhaust particles. This paper contrasts two propulsion concepts, one utilizing antimatter to induce uranium-238 fission and the other an architecture based on nuclear fusion. In both cases particles emanating from the actual nuclear reactions are focused and transmitted into space. While antimatter-based propulsion concepts have been proposed for several decades, the limited production of antimatter and its storage difficulties have retarded their development. The antimatter concept has been the subject of two past studies funded by the NASA Innovative Advanced Concepts (NIAC) program. With the exception of thermonuclear warheads, fusion reactors that output more energy than the energy input to achieve ignition have not yet been demonstrated. In this paper the suitability of several nuclear fusion channels (reactant combinations) are assessed, Onboard power systems for both concepts are also discussed. For example, a mission to the habitable planet Proxima b should have at least 100 kW for data communication back to Earth, AI-level computing, and a LIDAR system capable of studying Oort Cloud objects from both our solar system and the Centauri AB binary system. This paper describes the current state of these concepts in the context of both manned and unmanned missions to the exoplanet Proxima b. It contrasts the strengths and weaknesses of these approach in order to provide guidance to future studies.
Gerald Jackson received his doctorate from Cornell University in 1987 and worked until 2000 as an accelerator physicist at the Fermi National Accelerator Laboratory. Before leaving he designed the antiproton Recycler ring and served as its construction manager, marking the last major particle physics accelerator built in the United States. In private industry he developed commercial markets for antimatter, holding the patent on antiproton-based cancer therapy and authoring dozens of papers on antimatter-based space propulsion systems. Since 2020 he has broadened his propulsion work to nuclear fusion systems suitable for unmanned interstellar missions.