What is the purpose of putting another man on the moon?
IMO, Armstrong's concerns touch on a fundamental issue that extends beyond the space program, namely what should be the appropriate balance between fiscal expenditures that are largely expenses (no future benefit) vs. those that are largely investments (have long-term benefits)?
While it might be tempting for policy makers to embrace expenditures that have little future value (near-term bias is an attribute of human nature), especially as such programs typically have their own fairly sizable constituencies, sound policy should also take into consideration net long-term benefits. For example, what would be the implications for the U.S. if let's say another nation gains a qualitative edge in alternative energy? How about if another nation becomes the leader in space/space-related technologies? Either outcome would do more than impact U.S. living standards/growth vis-a-vis those other states. There would also be fiscal and national security implications.
In the context of the nation's fiscal challenges, investments on education, science, etc., are not the reason the nation is facing those challenges. Seeking better performance with respect to those investments is, of course, prudent. However, the core problem of structural deficits lies with the tax code/mandatory spending programs. Hence, if the nation is to address its structural fiscal deficits, it needs to focus on the source of the problem. Trimming investments that are not the source of the problem won't accomplish much. However, such moves could cede potentially sizable long-term benefits. Reduced competitiveness in tomorrow's growth industries could translate into reduced economic growth. In turn, that would mean fewer jobs created, lower incomes, less tax revenue, etc., than would otherwise be the case. In short, the nation could wind up saving very little in the short-term (and that misplaced focus could actually delay the necessary task of addressing the cause of the nation's fiscal imbalances) all the while sacrificing long-term benefits.
In fact, in its recent report on fiscal consolidation, the International Monetary Fund advised that nations reducing expenditures avoid disproportionately cutting investments that have long-term benefit. Instead, the IMF advised that countries focus on the causes of their primary structural deficits.