Governments should spend money on the things that generate the highest return to the taxpayer. This is why the government owns the roads, water delivery, etc.

I am having trouble following the logic. Why do you choose roads and water as things that "generate the highest return"? Is it because modern life depends on them? But then government should supply our food and housing as well. Private firms provide a lot of water too. Do you suppose profit-minded firms could not provide safe and affordable tap water? It wouldn't be perfect, but neither is what we have.

You mention many beneficial results of research spending. We could examine them one by one and ask how much public vs. private spending contributed to the result, and whether it would likely have appeared without public funding. (I might request that you pick one single example that you think makes your case the best. I am inclined to think that trucking and rail will favor my side.)

My larger point is that R&D is a kind of investment that sometimes goes to waste and sometimes produces valuable benefits that people are willing to pay for.

People who risk their own resources in R&D have good incentive to invest wisely. When they fail they bear most of the cost. When they succeed they share the reward with customers who enjoy the benefit. No one is forced to pay for the research, nor for the result if they don't want to.

Government directs investment of resources provided by others. People are generally not as careful with other people's money as they are with their own money. I provided some colorful examples of wasteful spending that no one ever hears about. I think it is morally dubious that money someone could have spent on a pair of shoes was given to someone who is unwilling to finance their own rubber-band research.

You and am_Unition advocate for NASA, yet you recognize that many people are indifferent to space science. If people don't care that "the human race became bi-planetary," should they be forced to pay for such programs? Are the benefits that resulted from government investment (1) only obtainable by government investment and not by private investment and (2) enough to justify the investments that don't pay off?

the government has tools that a private business does not AND SHOULD NOT have

One such tool is eminent domain, and it can effectively overcome intractable coordination problems, but it can also be abused. Just as we prefer to allow many guilty people to go unpunished rather than risk one innocent person being unjustly punished, I am willing to give up some efficiency to live in a world where people cannot be forced out of their homes at the whim of wealthy developers.