The problem with our space program is not the goal(s). No, not at all that. It is the short sighted edicts from certain key members of congress (and their staff) forcing NASA to build the slow motion train wreck pork rocket to nowhere that is the SLS (Senate/Shelby Launch System).
If the vast resources on that program, especially the ones in said senators district, were re-purposed to manage and support a multi-vendor fix price milestone based competition like commercial cargo and commercial crew to station but this time with the goals to:
1: Provide deep space launch services
2: Develop and deploy deep space habitats and propulsion systems
3: Deliver logistics to these mobile outposts
We would have a sustained and robust infrastructure to explore the asteroids, the comets, Mars, Venus, etc.
NASA has tremendous talent and resources that can do so much more if only the policies and direction were in line with the fact that launching to LEO or even GEO is now a road well traveled, and beyond GEO is not such a leap if we just leverage what we have so far and build on that.
No need for a big fracking rocket done the old way as if it was never done before, with cost plus and an army of oversight.
Now when we get to needing new stuff like in space nuclear rockets and reactors, building really big outposts, or outposts on new worlds, we'll be in uncharted territory.
The in space outposts are not such a big leap from ISS except:
1: Extra stresses due to propulsion
2: Way more radiation beyond LEO
3: Long duration may require artificial gravity (spinning)
4: If something goes wrong your on your own, it's a long way from home
All these are solvable we just need to put the resources on them for real and make it happen.
Yep we need those resources set lose to address these issues now. Not a decade or two from now when SLS grinds to a halt giving us a rocket we can't afford.