There is something you are not getting. Assuming a set of solar panels like those on the ISS, able to deliver 200KW near Earth and 100KW near Mars, one must sti

There is something you are not getting. Assuming a set of solar panels like those on the ISS, able to deliver 200KW near Earth and 100KW near Mars, one must still convert that power to useful thrust. That means achieving fusion break-even, a requirement that the NASA documents explain. Obviously ion thrusters aren't practical for this kind of heavy lifting and short mission time, but that doesn't usher in fusion power as an obvious substitute -- unless the project creates a useful reaction, meaning a gain > 1.