But they have a disproportionate impact on mindshare -- on defining what the limited supply of professional scientists and engineers perceive as the most interesting and important problems to solve. This is a zero-sum game: every minute a bright college student spends talking about rockets is a minute that she's not talking about ecology.

> But they have a disproportionate impact on mindshare -- on defining what the limited supply of professional scientists and engineers perceive as the most interesting and important problems to solve.

The supply of talented (as opposed to just "professional") scientists and engineers is quite large and growing all the time. Space exploration, IMNSHO, is just as important as ecology, in the first place. However, there will still be plenty attracted to that discipline.

Believe it or not, the best and brightest are among the most motivated to seek their own interests.