Transit time nomogram, courtesy of Atomic Rockets

Using the attached nomogram for computing brachistochrone trajectories to other bodies throughout our solar system, I am working with the assumption that this spacecraft travels with a constant acceleration of 1/3 g (right around where the acceleration column says "Mercury/Mars").

The second-to-the-left column of the nomogram lists various drive systems by their thrust capacity in newtons. Where on that column could I plug in a metallic hydrogen rocket?

Edit 1: What value in newtons would correspond to such a drive? You can pretend that you are a mad space scientist with access to experimental tech and near-unlimited funds.



1 Answer 1


You place it wherever you want.

Unlike specific impulse, thrust is not an inherent property of a fuel. Every one of the entries in the second column refers to a specific engine design. If you need more thrust, you just make the engine bigger (or add more of them), keeping in mind that doing so will increase your vehicle's fuel requirements and overall mass.


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