Speaking generally, it should be obvious to everyone that our ability to launch objects into space has dramatically transformed our lives. Though it's been just over 60 years since the Soviets launched the first satellite, it would be hard now for most people living in the developed world, and even many in the developing world, to imagine living without the satellite technology that so much of our communications system depends on. Satellites have also been key to our understanding of problems such as climate change and its effects on the world, and study of the Sun and other planets has been and will continue to be vital to understanding climate change. For the future, some have envisioned using satellites to collect solar power in space to be beamed down to Earth, potentially solving all of our energy problems in a manner that would minimize environmental impact. Of course, none of this necessarily requires a human presence in space, so the question of the value of missions like Apollo still remains.
It must be acknowledged that the space race of the 1960s was a product of the Cold War. If the US and the Soviet Union had not been in such intense competition, it is unlikely that humans would have gone to the Moon, at least at such an early date. But this does not take anything away from the achievement. Of course, many question whether the human race is any better off due to the fact that humans have been to the Moon. In fact, achieving such a difficult technological feat forced a rapid development of many different types of technology, many of which proved useful in other fields. Today, the space program continues to be a major driver of technological development. But practical considerations aside, there's also the inspirational factor. The Apollo missions inspired many young people of the time to enter careers in science, so unless we argue that science is of no benefit to humanity (and many of the world's problems, climate change foremost among them, will not be solved without science), then the Moon landings certainly did some good. The current space program has been less successful in inspiring young people in this way, but this is because for most people, it takes something dramatic like going to the Moon (or, in the future, Mars) to really grab them. And while our chief priority should be creation of an equitable society where every child can realistically aspire to lofty goals, we also need to provide those lofty goals. While I wouldn't see anything wrong with my child aspiring to follow in the footsteps of Michael Jordan or Madonna, all things considered I'd prefer it if she wants to follow in the footsteps of Neil Armstrong and Buzz Aldrin.
But to take another angle, we should ask ourselves what we would gain if the money spent on space, whether in the past or the present, had been diverted elsewhere. Many people seem to have the idea that NASA has an enormous budget and that huge sums have been and are spent on space. And indeed it's true that major space missions, especially if they involve human spaceflight, can have price tags in the billions. But we have to put these numbers into perspective. The annual NASA budget over the past several years has been in the neighborhood of US$15 to 17 billion. This compares to over US$500 billion for the Defense Department, not including discretionary spending, debt servicing, and many other military-related costs. Half a dozen military procurement programs have annual budgets that equal 20% of more of NASA's entire annual budget. Since the early 1990s, NASA's annual budget has been less than 1% of the total annual government budget. Congress is now debating a health care reform bill that many people consider highly inadequate but which nevertheless is projected to cost US$1 trillion. If NASA's budget were devoted entirely to health care, it would hardly make a dent in that. In fact, all of the money spent by NASA in the 51 years since its founding in 1958 totals US$416 billion, less than a single year of the US military's budget and less than half of the price tag of the health care bill. Even if inflation is taken into account, the figure is US$806 billion, still less than a trillion dollars over a period of more than half a century, not really all that much relative to government spending as a whole. While spending on NASA may not bring any direct benefits to impoverished and disadvantaged people in the US or elsewhere, the US government spends plenty of money on much worse things.
The space program's problem is not really that it's so expensive, but that it's an obvious target. The money that goes to a lot of government programs is only visible to most people as abstract numbers in the budget, while the space program is something that everyone can see. But if anything, that should be evidence that we are at least getting something for our money (though I would not dispute the fact that NASA, like other government agencies, has often been guilty of major incompetence). Another problem is that it is easy to contrast our achievements in space with our lack of them here on Earth. People say things like "How can we send people to the Moon when people are starving on Earth?" But the same question could be asked of many other things the government spends money on, not to mention private spending (how many billions do people spend on cosmetics, sports or movies every year while others starve?), and most of them are clearly less beneficial than the space program, if not downright harmful. And even if all the money spent on space were spent on poverty alleviation, there would not be a noticeable impact on poverty.
Ultimately, however, the reason I find self-professed progressives who argue against spending money on space so disappointing is that I expect progressives to have more vision. Human expansion into space over the next centuries can provide us with a greater understanding of our world and the universe it inhabits and lead to improvements in technology that can benefit everyone. What's more, in the short term attempting the difficult task of trying to live in a colony on the Moon or Mars will provide valuable lessons in how to manage our environment in a sustainable way, and in the long term going into space will give us opportunities to create new societies in which we can attempt to put progressive ideals into practice without the centuries of cultural baggage that exist in terrestrial societies, in turn setting an example for those back on Earth. Certainly, this will not happen until far in the future, but progressives should be able to take the long-range view, attempting things that will benefit future generations, if not those alive today. Progress doesn't just mean improving our world of today, but looking to the future for the good of all humanity. The space program can be an important part of that future, if we devote but a tiny percentage of our effort to it.