One of the few things that I think very clearly falls into the sphere of things government is best suited to do is long range research. Which is why stories such as this on declines in NASA's basic research capacity make me reflect on how badly we allocate our expenditures. If government won't do it, who will? To paraphrase a conversation I had with my supervisor today (on a completely unrelated subject) businesses "pay people to develop a better paint for refrigerators or a better motor. You won't be spending their money on finding a way to grow plants on a trip to Mars."
There should be a fairly obvious division of labor here. Government can do the pie in the sky type stuff that is too risky for any investor. Investors can develop the processes that will let us bring the successful portions to market. I think we're still a ways off profitable space travel so lets keep the basic research well funded.