I think the question is not whether it's a good idea to return humans to space (of course it is), but what it will accomplish and at what cost.
You can make observations such as, "You have to feed the soul, too!" (from The West Wing after Josh mocks the cost of Mars Direct). However, there are serious problems on Earth in the U.S. that cannot be solved by developing manned spaceflight tech, and those concerns are going to override thoughts about manned spaceflight for most people most of the time. What drove the space program (first unmanned, then manned, then to the Moon) was national pride and the desire to out-compete the Soviets. I don't see any available current of feeling that could generate similar support today.
Ignore the Shuttle for a moment and imagine we'd kept human-carrying spacecraft perched on top of rockets, like we did before; in other words: safer, cheaper, manned spaceflight in the modern era. What has manned spaceflight achieved in the last 30 years? We've serviced some satellites, certainly, but at what cost compared to simply deorbiting them and launching new ones? Experiments in space have advanced medical and materials science technology somewhat, but consider how far we could have advanced if all the money thrown at the Shuttle and ISS programs had been allocated to automated/remote-controlled experiments and, where possible, simulations. Whatever the difference is, those are missions where you could make a case for a manned mission to conduct experiments, but I doubt there would be very many.
Next, let's imagine a hypothetical Zubrin-inspired mission to Mars. It would inspire everyone, but for how long? People don't stay inspired forever, and suppose it becomes apparent that we'll never go back to Mars again because the cost/benefit is too high, or heaven forbid if the mission fails because the astronauts die unexpectedly. Things on Earth become worse because the hope of productive Mars missions will have dimmed.
Americans have become much more risk-averse. I think that without a strong and sustained reason for sending humans back to space on a long-term or regular basis, we shouldn't bother. Space is not a very nice place for humans, even with all our technology. There's plenty of inspiration available by accomplishing things in space without risking astronauts' lives to do so.
> "However, there are serious problems on Earth in the U.S. that cannot be solved by developing manned spaceflight tech, and those concerns are going to override thoughts about manned spaceflight for most people most of the time."
If you spent the entire US Federal budget fighting worldwide poverty, you'd end with less than $500 to spend on every person every year.
We should not spread wealth and advantage thin trying to fill in every low point. Even the Bill and Malinda Gates Foundation doesn't wait until everyone is vaccinated before putting money to other "higher level" activities such as research. Moreso, I am glad that there are charities which primarily concern themselves with providing large amounts of money to speculative research instead of spreading that money thin on lower level concrete but ultimately fleeting activities. All that cancer research money could be spend paying the hospital bills of people who are currently undergoing treatment, but I much prefer it being spent on research.
Charities that focused on paying hospital bills would be great, but not at the expense of charities which focus on research. There is room for both, but we should not cut back on funding for high level research and advancement because there are still low-level concerns to be addressed.
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Alternatively, more succinctly: If we had spent all that Apollo money on malaria instead, would we still be fighting malaria today? I think that is near certain.
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Alternatively, more metaphorically: If you are tasked with tracing the outline of a Koch snowflake and tracing the outline of a square, would you hold off on tracing the square until the Koch snowflake was complete?
What has manned spaceflight achieved in the last 30 years?
Just in terms of encouraging political cooperation between Russia and the USA with the ISS, it has been priceless.
Other than that, we are learning about human spaceflight, if you think that is not worth the bother in and of itself, then ultimately you are choosing from a dark selection of futures.
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There's plenty of inspiration available by accomplishing things in space without risking astronauts' lives to do so.
If you don't risk astronauts' lives by sending them into space, then you don't actually have any astronauts at all.
You can make observations such as, "You have to feed the soul, too!" (from The West Wing after Josh mocks the cost of Mars Direct). However, there are serious problems on Earth in the U.S. that cannot be solved by developing manned spaceflight tech, and those concerns are going to override thoughts about manned spaceflight for most people most of the time. What drove the space program (first unmanned, then manned, then to the Moon) was national pride and the desire to out-compete the Soviets. I don't see any available current of feeling that could generate similar support today.
Ignore the Shuttle for a moment and imagine we'd kept human-carrying spacecraft perched on top of rockets, like we did before; in other words: safer, cheaper, manned spaceflight in the modern era. What has manned spaceflight achieved in the last 30 years? We've serviced some satellites, certainly, but at what cost compared to simply deorbiting them and launching new ones? Experiments in space have advanced medical and materials science technology somewhat, but consider how far we could have advanced if all the money thrown at the Shuttle and ISS programs had been allocated to automated/remote-controlled experiments and, where possible, simulations. Whatever the difference is, those are missions where you could make a case for a manned mission to conduct experiments, but I doubt there would be very many.
Next, let's imagine a hypothetical Zubrin-inspired mission to Mars. It would inspire everyone, but for how long? People don't stay inspired forever, and suppose it becomes apparent that we'll never go back to Mars again because the cost/benefit is too high, or heaven forbid if the mission fails because the astronauts die unexpectedly. Things on Earth become worse because the hope of productive Mars missions will have dimmed.
Americans have become much more risk-averse. I think that without a strong and sustained reason for sending humans back to space on a long-term or regular basis, we shouldn't bother. Space is not a very nice place for humans, even with all our technology. There's plenty of inspiration available by accomplishing things in space without risking astronauts' lives to do so.