There are far more feasible alternatives to deep space propulsion that could actually work now, and all you have to do is detonate a couple of nukes.
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
See also its cousin:
https://www.centauri-dreams.org/2012/07/20/medusa-nuclear-pu...
You can even try these in KSP with mods afaik