I suppose you could say much the same about lots of advanced scientific research. There's not going to be any short term payback, but I bet there will be a long term payback. Advanced research is like that - at first it seems to have no practical value, just abstract knowledge for its own sake, but later on knowledge gained in the course of constructing and running the experiment finds application in all sorts of other areas.
Consider the moon landings 40 years ago. No large deposits of valuable minerals were found, or anything else of much practical value. But the advanced technologies which were developed to make the missions possible have been utilised in a myriad of other applications. I sleep on one of them at night (a memory foam mattress) and my back is a lot better for it.