As the debate about the future of our space program moves from investigating what went wrong to what is to be done in the future, we should take a leaf from the US Air Force book.
The Air Force, like NASA, initially resisted the use of unmanned flights, the introduction of missiles, and then the use of drones because - among other reasons - they needed no pilots, and offered no glory.
Drones, like the missiles before them, cost only a small fraction of the cost of a fighter or a bomber, and have proved to be very effective in Afghanistan for missions such as lingering over a target area, and flying slowly. When one is shot down, as in Iraq recently, the military didn't have to worry about the lives of a whole crew or try to evacuate the pilot from enemy territory. These drones are, though, flown by some guys sitting in a bunker many miles away, manipulating a joystick. No machismo, no honor.
The suggestion that NASA should rely to a great extent on unmanned flights is as old as the space program. The vehicles involved are, of course, much more powerful and expensive than the drones the Air Force uses, but they still cost only a fraction of what a shuttle does, do not have to be flown back - say, from Mars - and do not endanger anyone aboard, because no one is.
Although rarely discussed in this way, the greatest achievements of the space program - whether by NASA, the military, or the private sector - have been the result of unmanned vehicles and instruments. And, by the way, most of those were in near, not deep, space. Thus we have achieved giant improvements in worldwide communication, navigation, mapping, weather forecasting, and above all surveillance by unmanned satellites.
A key example is Global Positioning Systems (GPS) that allow ships, cars, and bombers to establish their position within inches - of great merit for locating the enemy.
In comparison, manned flights into deep space yield surprisingly little. Many Americans, who have been taught from childhood to admire the nation's astronauts and their heroic achievements, are reluctant to hear that we've learned precious little from quick lunar visits. The moon didn't serve as the military high ground Americans were originally promised; no riches were found there for anyone but rock collectors; and the scientific experiments conducted in outer space yielded much less than those conducted on Earth, and many could have been carried out by robots.
I know all too well how unwelcome such hard-nosed comments are. When I made such observations in my book "The Moon-Doggle," published in 1964, I was raked over the coals by NASA officials and a fair number of space enthusiasts.
But I was hardly alone in suggesting that a good part of our space program could be carried out by unmanned flights. The General Accounting Office issued a report in 1973 that explored this option, as did the Rogers Commission, convened after the Challenger blew up. Several scientists - for instance, the University of Maryland physicist Robert Park and the Duke University historian Alex Roland - have argued that machines do a better job than people in space exploration.
Two major explanations are commonly given for NASA's persistence in devoting so much of its $15 billion annual budget to manned programs and so little to unmanned ones.
The first is that because manned vehicles cost much more than unmanned ones, they're strongly favored by the space industry. It doesn't have to lobby hard because NASA has placed many of the construction projects in districts of members of Congress who approve its budget. The NASA budget would be cut if it abandoned manned missions because American voters prefer seeing the Stars and Stripes in space to canned images of planets.
The second explanation is the spiritual importance of manned flights to the nation. When all else fails, NASA waxes poetic about this. Marcia Smith, a congressional space-policy analyst, said in a recent interview on CBS that key to NASA culture is the belief that sending people into space is inherently part of humanity's destiny to explore. And Mike Mullane, a former astronaut whom NASA likes to parade as a spokesman, holds that these things are what being human is all about - a celebration of ourselves. Just as the world would be less if it didn't have symphonies and ballets, it would be less if it didn't have space exploration.
But there's precious little evidence that manned space trips without calamity do anything for our soul; they've become routine. And we have plenty of new heroes - police and fire crews who dashed into the World Trade Center, for example.
I'm not arguing that there aren't some missions for which astronauts would best serve. But these should be carefully sorted out rather than allowed to prevent coolheaded analysis with grand but indefensible claims. The lives of some of our best are at stake.
• Amitai Etzioni, the author of 'The Spirit of Community,' is University Professor at George Washington University. As a sociologist who specializes in contemporary American society, he has testified before Congress on NASA budget issues.