[Spaceships] Fusion Rockets vs. Reactors

[the-red-scare]

A fusion rocket is simply a fusion reactor that heats reaction mass and a magnetic nozzle to aim it out the back. An SM +10 TL9 fusion rocket generates 50 tons of force with a specific impulse of 36,000 s for a jet power of 79,000 MW. At 500 tons for the drive that's 158 MW/ton including all the stuff that isn't the reactor.

An SM +10 fusion reactor produces 2 PP. Depending on your assumptions about what a Power Point is, a TL9 fusion rocket has a reactor that is around 80 times as powerful as a standard fusion reactor. By TL12, even assuming super fusion reactors are the default the fusion rockets are about 1,500 times as powerful as the reactors.

Real-world designs for fusion rockets are generally in the 1-10 MW/ton range at best, with a couple more fanciful versions approaching 100 MW/ton. Even the first generation TL9 rocket outperforms these. Realistic fusion rockets matching Spaceships reactor outputs with the bare minimum accceleration to be useable could see a role in a hard-science universe.

Fusion Rocket (TL9): 0.0001G, 7.5 mps per tank
Super Fusion Rocket (TL11): 0.0001G, 15 mps per tank

High-Isp versions for Kuiper Belt and intestellar travel could be workable.

Optimized Fusion Rocket (TL9): 0.0000015G, 520 mps per tank
Optimized Super Fusion Rocket (TL11): 0.000003G, 520 mps per tank