Challenge ? For the individual and its patrons, sure. The country or company ? Its lured by the competition and wanting to be the one winning the prize. But a

Challenge ? For the individual and its patrons, sure. The country or company ? Its lured by the competition and wanting to be the one winning the prize. But as a society ? When the inevitable "why fund space travel / fundamental physics / ..." question is asked ? Side gains is where it's at.