Having digested that gobbledyguck, I will now attempt to respond to the late Ms. Arendt's rather lengthy comments. The original question was, more or less, "What has the conquering of space done to the stature of man?"
I think it is unquestionable that the exploration of space (conquering is a bit presumptuous at this stage) has improved humanity's stature as a whole. In addition to developing technologies that have taken our machines and ourselves to an entirely new and hostile environment, we have broadened the scope of human activity as well as our understanding of the universe. Furthermore, the machines, materials, organizational techniques, and knowledge gained from space exploration have been used to improve life here on Earth. All of those are positive goods.
However, the legacy of our exploration has been mixed, as it is with nearly any human activity. The glorious image of our home planet seen above the moon from Apollo 8 was both an inspiring image of beauty as well as an inspiration to the environmental movement, which has had many positive impacts upon the way we interact with our world.
However, extremists in this movement have stopped new technologies that might have led to additional advances or even activities that might have improved the environment further. Many people are convinced that we have only "one world" with limited resources, which is true, to a point. But this ignores the resources of the solar system we have only too briefly explored. We need both energy and materials to maintain our economic and cultural way of life; those resources are abundant in space, and yet space has been short-sightedly ignored and neglected since 1972. Some have said that we need to stop exploring space until we make life perfect here on Earth, an unlikely event in any number of human lifetimes. Indeed, the retreat from space has diminished humanity's stature, from a philosophical point of view.
Another viewpoint--not related to space, but affecting its future--states that "We shouldn't explore or settle other planets because we have already fouled up this one, and we shouldn't spread our nastiness throughout the solar system." This could be based in environmentalism ("We've polluted the Earth!") or traditional religion ("We're fallen creatures and cannot be trusted to make good just because we change locations"). It might also be true, as suggested by historian Jacques Barzun that Western Civilization truly lost its confidence and soul in the First World War. Whatever the origins of this line of thinking, the end results are a lack of belief in either man or his works. This, too, represents a philosophical retreat from human betterment, which certainly cannot be good for us as a people.
So the question becomes, 40 years after Arendt's essay, not what is the impact of space, but what human beings have done with themselves since they started exploring space? It's one thing to go boldly where no one has gone before and then live up to it. It's another to go boldly, take a few rocks and pictures, and then go back home. Arendt wondered what humanity would do with its new powers in space; I doubt she gave serious thought to the idea that we would go into space and stop. She might have responded with dismay: "How shameful, how cowardly."
Exploring space was a true leap into newness. As a government activity, the race to the Moon was truly a liberal adventure. Eisenhower and his presumed disciple Nixon were content to develop aerospace planes on a slow, steady track. Ballistic missile-powered spacecraft were distractions, government action was unnecessary. The NACA model of space development (government does the R&D, the private sector develops it) was just fine, thank you. So if the progressive, future-embracing liberal Democratic party turned its back on space, what then is the public to expect of the conservatives? Certainly not a gargantuan space program on the NASA model.
I must return once more to the failure of vision when it comes to the reasons people give for no longer exploring space:
- We must make life perfect here, which has a subset assumption, i.e., the money spent on space could and should be used for more worthy problems here on Earth.
- We've screwed up life here; we shouldn't pollute the rest of the universe.
Item 1 is a retreat from greatness and achievement. Perhaps the loss of faith in government (thanks to Vietnam and Watergate) caused progressives to give up on the idea that America could do good in the world. Or perhaps they just changed their priorities on what they meant by "doing good." But needless to say, the John F. Kennedy vision of "bearing any burden" in the pursuit of liberty--including the exploration of space--no longer holds sway.
Item 2 is self-indulgent nihilism: humanity is the ultimate evil. We've destroyed the planet; we'll destroy anything else we touch. We're scum. We'd all be better off if we were zapped by an asteroid and replaced with the cockroaches. The only way to expiate our sins of militarism, racism, sexism, capitalism, pollution, etc. is to withdraw from space, apologize to all our victims, and commit cultural suicide. What utter bilge.
The only way for cultural mores to survive is for enough people to believe in them. We've now got a second generation (or so) being raised not to believe in the West's values of personal betterment, capitalism, and scientific progress. A frightening number of young people don't even believe we went to the Moon in the first place (one astronaut's great retort to this: "Then why did we fake it six times?"). We have junk science and conspiracy theories in the place of science and engineering. Were I better educated, I might have had a better shot at understanding Hannah Arendt's essay in the first place. The stature of man has fallen since Apollo 11: philosophically, technically, and morally. Space exploration serves to uplift us and inspire the best in us. Turning our back upon it has only been to our detriment.