Hello, Peter,
First, I probably could be convinced that at the time the Apollo program was a legitimate expenditure of taxpayer money -- if it could be connected convincingly to the cold war.
First, thanks for your detailed response. A substantially more useful contribution to the discussion than three smilie faces.
That the Apollo Program was a response to Russian space sucesses is a matter of historical fact. The same goes for NASA's success. Have you never seen an image of the moons of Saturn and felt a little twinge of awe? Or pride?
What’s the difference between a public library and an opera?
Any operas I've attended required you to purchase a ticket in order to attend. This is not true for a library. Thus, opera is at least partially supported by free enterprise. (something I support, BTW. The success of free-enterprise SpaceEx is notable.)
Why, exactly, should taxpayers be forced to support a library?
Because if they don't, hardly anybody will. Can you imagine today's publishing industry supporting the idea of libraries? Or authors thinking libraries were a good idea?
Absent "enforced" (your words, not mine) public support, libraries would never exist.
Don’t get me wrong, I love libraries and before the web matured I used to spend a lot of time in libraries.
Thus rendering inexplicable your lack of support for funding them.
Unfortunately, I see cases where taxpayer money is being used nowadays to support operas. The NEA is an abomination when you consider that Joe, the guy who works in the Chrysler press plant, and will never go to the opera, is having his pocket picked by his government to support the opera.
FWIW, I'm not an opera fan. I do think, however that the total dollar figure "picked from the pockets" of the boys in the Chrysler plant to support opera is vanishingly small.
We can discuss your “entire families going bankrupt because someone got sick” if you want to, but it’s a complicated subject that leads to people not needing to work as long as taxpayers are being forced to provide them with everything they need.
Another vanishingly small percentage, yet one frequently cited by the right. In the Socialist Hell that is Canada, there are very very few who refuse to work, yet are treated "for free." And no families go bankrupt because somebody got sick. It's just a better, more efficient, more fiscally responsible, more caring idea to look after each other, healthwise. Most western democracies realize this.
The bottom line is the question of whether or not it’s moral to force people to give up their earnings for a “program” YOU think is a good idea.
Actually, it's usually programs that are supported by the voters. We've just easily identified five. There lots more.
Can you imagine a free-enterprise highway system? Ain't gonna work. We've both experienced the highway systems in areas where supportive taxes are low. I think they're actually corruptly financed by the shock absorber industry.

There’s no such thing as government money. It all comes from you and me and the rest of the taxpayers.
Actually, I think we all know this. We don't need this particular bell rung over and over and over.
And no, it doesn’t “disable all forms of taxation” as legitimate. A society needs the other three things in order to survive as a society. Without a military the society will be invaded. Without police forces the society will degenerate into a shambles. You can see the beginnings of that one in New York, Chicago, LA, San Francisco... And without a fire department you’re dependent on your garden hose.
My position is that there are far more than just "three things" that society needs in order to survive that are supported by taxes It's just that the anti-tax-at-all-costs faction refuse to see them.
Right-side-of-the-spectrum Alberta, for instance, recently fired a few thousand nurses and cut many more essential services in order to balance their provincial budget. Other than the outlier-case of Yukon, Nunavut, and the Northwest Territories) Alberta is the only province which refuses to invoke a sales tax.