In the current political climate, the biggest threat is to Earth science, which is increasingly devoted to climate change. It may not be a coincidence that conservatives in Congress have been systematically trying cut NASA’s Earth Science budget in favor of planetary exploration, albeit unmanned exploration. They argue that the goal is to refocus NASA on its traditional mission. But that’s a smokescreen, because research in climate science has become a major part of NASA’s mission. They’re really displaying their hostility to research that could undermine the fortunes of their patrons, the fossil fuel industry. If Trump’s call for manned planetary exploration is another puff of that smokescreen, it would hardly be surprising.
Sending humans into space would give Americans a sense of mission and grandeur, but that’s mostly a sign of civic immaturity. Take the same sums and spend them on curing disease — whether the biological malady of cancer or the social maladies of poverty and hunger — and pride will surely follow. Keep the astronauts at home, and there will be much more money available to send robots farther out than humans could ever go, and to bring back immeasurably more knowledge.