Agreed. Unmanned missions are a much better value in terms of the science gained per dollar spent. At one time, the additional media attention and public interest in manned missions may have had some PR value, but even that public interest waned long ago.
As exciting as it would be to send people to Mars, for example, we taxpayers will get a much greater return on our investment if we continue to explore Mars and other worlds with unmanned vehicles.
Another reason the cost has gone up so much is the mission. What is the goal of recent plans? Don't worry, nobody else knows either. What was the goal of Mercury, Gemini and Apollo programs? Most can tell you it was to get a boot on the moon before 1970 (and hopefully before the Russians). Without a clear mission or goal how can one estimate a budget?
Great subject. I've come to the conclusion that manned space flight is dead, but I have great hopes for maintaining unmanned missions. Why is manned space flight so expensive? You & other commenters identified some key reasons, particularly the "risk" factor: the media will continue to treat any manned mission fatalities just like an airline crash, and public pressure will force NASA to respond with doubled-down safety measures. $$$$$ -- and say goodbye to future budget approval from Congress.
But the real reason is that space is an incredibly hostile environment for biology. Compensating for that will always be ridiculously expensive. We should stop bemoaning this fact, and open our eyes to the amazing unmanned capabilities sprouting around us due to efforts from our own electronics industry. That's something to celebrate and look forward to.
I agree with rf_austin.
Bill, to answer your questions, "Yes" to all :-)
Honest assessments and estimates are rarely received favorably or accepted as a best guess (too slow/expensive/unreliable). Engineers are either forced to give overly optimistic estimates to keep their job, or are replaced with ones who will give the desired answers, regardless of reality...
I realize that we need schedules and estimates...but they are just that: ESTIMATES. I am appalled at the inability, whether willful or not, of nontechnical people (and even technical people who are performing project management) to understand and/or acknowledge this FACT: You don't know how long it will take until you do it. And if you have not done it before (that is, it's NEW), well, QED.
In my experience, cost and schedule overruns are due to the following causes:
* Overhead/bureaucracy (they cost time and money)
* The genuine unexpected/unknown problems that come up
* Actual poor engineering (a VERY tiny percentage)
Oh, and for a technical comment: a manned payload has to carry more weight; life support is needed, and part of the payload is devoted to return/reentry. That costs.
In the mid-60's, the US had a schedule driven space program "... land a man on the moon before the end of this decade". Along the way, we lost three astronauts and almost lost several others (e.g. Apollo 13). These astronauts were test pilots who were used to taking risks and their contemporaries in the military did indeed regularly lose lives. With the Space Shuttle, the US began to describe the vehicle as the "space transportation system" and positioned it for "school teachers" and even the elderly. Because of public (and political) sentiment, they lost sight of the fact that launching folks on a rocket is an inherently risky business with complicated technology and you will lose lives. We should make space transportation as safe as "reasonably" possible given the inherent risks and not try to make it safer than my morning commute to work (which by the way isn't all that safe either). Somehow we are willing to tolerate lives lost commuting to work, but heaven forbid if they blow up in spectacular sheet of flame. We then proceed to over-design and graft on safety features of doubtful value, but very real and large expense.
Another aspect of this is that cars are used daily and we've engineered a lot of safety into them. Space shuttles are used infrequently and safety upgrades are done infrequently as event and cost will permit. Perhaps if we were building spacecraft as often as we build cars, greater safety could be built in at lower cost.