I'd be very surprised if they're genuinely out of research ideas to test in space. If that is actually true then humanity has a problem.

>research that couldn't be done with automation

I'd think there is room for both. Automation makes sense, but don't think the versatility of meatbags is entirely there yet.

An entirely different form of research could be done by sending large quantities of normal people into space. Astronauts are such a small sample size (and so thoroughly vetted) that you get a different statistical view.

Horses for courses micromanagement business administration and lobbying gravy train.

Maintain american capacity to put technicians in low earth orbit. People forget a big part of the shuttle mission for example was to capture and put technicians not just on your satellite but any satellite the shuttle was capable of intercepting and getting into the bay. Consider the fact that the shuttle didn’t really die, in fact the airframe form is still flown but its mission is now classified.