I believe the only sound argument for government-funded manned spaceflight is to encourage and inspire more people into science and engineering. That's the only economic, scientific, and political argument with any robustness.
For the most part in the present time I will agree with you. The hard benefits in manned spaceflight are long term as the technology and techniques develop and mature. But right now Manned spaceflight is technically still in its infancy. Well maybe in it's terrible two's
Unfortunately there aren't sufficient devoted funds in the US and Europe to continue all space science-type research to the current excellent level AND develop a proper manned spaceflight programme. Something has to be axed. What would you choose? Probe to Pluto? Climate research? LHC?
If I had my druthers I wouldn't cancell any of it.
But Manned flight has been cancelled before. And I believe we have suffered a loss because of it.
Apollo's long range plans were to end in a long term lunar presence with a research base.
It never had the chance to even try. (They even built a roving platform that was based on the Lunar Module cabin. It is presently being refurbished to be dispalyed at the Smithsonian)
If it had been allowed to continue we could have had an established presence there already.
NASA knows that it is public opinion that drives the purse strings. And all those things you mentioned in your first statement NASA hopes will convince the people to loosen those purse strings.
Sadly, NASA seems to be dropping the ball in that area.
Although it is doing great given the circumstance in robotic exploration.
But then that was never cancelled.
The science can be achieved by probes and robots (albeit at a possibly slower rate), while the possible technological benefits of manned spaceflight are possibilities, not definites. We definitely will (and do) get many benefits from concentrating on the more affordable probes and robots.
Back in Apollo's era those benefits were definite. People who lack or lost the ability to control thier body temperature have Apollo to thank for thier freedom. The development of micro-computers that lead to the desktop or laptop your using to read this owes it start to Apollo also.
If manned spaceflight hadn't been canceled back then those benefits would be closer to being definite now.
The arguments flavoured with exploration, great human achievements, we won't know until we do it, etc. can and most likely will be achieved by the private sector eventually.
I agree. Especially so if NASA is forced to kill manned spaceflight. Right now NASA is our only ride untill the private sector gets up to speed.
Other countries are just now getting involved. China is pushing forward with manned launches of thier own. So far they have put three people up there on thier own, and India wants to get in the game.
It's all good in my eyes. But as an American I would hate to see my country give up on it as other other countries push forward.
It's a difficult decision, and I'm glad I don't have to make it!
Well I glad that you see that there is some value in manned space flight. Not many can see it.