Referring back to the conversation Buck and I were having about what might be a good economic incentive to kick start space exploration in a big way (Lunar Lander Odysseus lying sideways, BuckGalaxy February 24, 2024 12:45 pm), here is a possibility. A few years ago, the British Interplanetary Society published a preliminary engineering study for an unmanned fusion-powered interstellar probe (https://en.wikipedia.org/wiki/Project_Daedalus) designed for a mission to Barnard’s Star. The proposed propulsion system required a fuel that is not available in large quantities on earth…

Daedalus would be propelled by a fusion rocket using pellets of a deuterium/helium-3 mix that would be ignited in the reaction chamber by inertial confinement using electron beams. The electron beam system would be powered by a set of induction coils trapping energy from the plasma exhaust stream. 250 pellets would be detonated per second, and the resulting plasma would be directed by a magnetic nozzle. The computed burn-up fraction for the fusion fuels was 0.175 and 0.133 producing exhaust velocities of 10,600 km/s and 9,210 km/s respectively. Due to scarcity of helium-3 on Earth, it was to be mined from the atmosphere of Jupiter by large hot-air balloon supported robotic factories over a 20-year period, or from a less distant source, such as the Moon.

This is precisely the type of high value project that might yield incalculable benefits, then again, it might provide absolutely nothing of any conceivable value.

Maybe there IS a minable source of He3 out there in the solar system… Maybe even on the moon. But who’s going to invest the $ needed to find out?