How would it look like to use a fusion reactor to power a spaceship?

Edita Bromova

(Source: © Gasi /

One can read about what a fusion reactor power plant would look like but this amazing technology could power spaceships! We would finally explore our Solar System properly. Would that work? What advantages would fusion reactors in the propulsion of spaceships bring us and what would their use look like in practice?

The use of fusion reactions to power spacecraft is still pure speculation but in principle there would be two possibilities. The first option is that the electricity produced by the reactor would be used to operate some revolutionary, not yet discovered type of propulsion. Then a fusion reactor on a spaceship would work on the same principle as an earth reactor producing electricity in a power plant. It would probably be a tokamak or stellarator. It would be large, demanding service and spare parts, but in turn very safe to operate. It would probably require a small nuclear reactor to “start up”. The second option is that fusion would generate hot plasma that would be used as jet propulsion. The concept of a closed stellarator or tokamak does not fit here. The best would probably be an open magnetic trap that would use magnetic mirrors to direct the plasma into the jets. As a fuel, it would be appropriate to use helium3, which can be easily mined in space on the surface of barren moons and asteroids. The use of a certain type of inertial confinement is also being considered. A series of fusion microbursts behind the spaceship would vaporize the ablation shield, which would then reactively propel the spaceship forward. In this case, powerful lasers would probably ignite small pellets of fusion fuel.

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