You know, there's. There's a potential for more advanced, more efficient thrust engines, and probably one of the most promising ones in the near term is actually a nuclear engine, a nuclear thermal rocket, where instead of using combustion to propel hot gases out the back of your nozzle, you actually use a nuclear reactor, and you take hydrogen, you flow it over that, you heat it up like, super hot and shoot it out the back without lighting it on fire. And if you do that, you can actually get much more thrust with much less mass of fuel, like a smaller fuel tank, but more thrust, thrust over time. So that's one possible way to go.