>>22896136 (OP)you say that, and it makes me laugh—I can't help but imagine you're thinking only of chemical rockets
are you aware of the concept of propulsion using external magnetic fields to provide angular momentum to mix spin-1 and spin-2 fields?
no reaction mass; asymmetric spacetime curvature waveriding via Gertsenshtein
you fire a highly coherent, collimated x-ray laser into a nested EM field, you get sympathetic resonant 'photogravitic' coupling between the spin-1 (EM) and spin-2 (gravitational), and you fall upwards without... actually moving at all
very little mechanical stress; no acceleration on the craft itself; beam steering via EM field modulation, not dissimilar at all to an old CRT
if you're not familiar:
>https://www.sciencedirect.com/science/article/abs/pii/S2212686423000213crazy, right?