The fuck do you mean dead-end? You think we’ll just keep using chemical rockets until the end of time? Nuclear propulsion is the most efficient form of propulsion we have at the moment. Iirc, nuclear engines would dramatically cut down on travel time because you can burn for much, much longer due to their efficiency. The only reason we don’t really use them is because everyone loses their shit and has a panic attack the moment you float the idea of putting a nuclear reactor in space (we still use RTGs though).