I don't think it's neccesarily the selling of Mars in particular. I'd venture that most people go through huge stretches of time without once thinking about space exploration, and the whole rationale behind spending money to put people in such a hostile environment is not something with which they readily come to terms. My brother, love him though I do, is a case in point. He'd have no problem whatsoever with the total abandonment of human spaceflight.

There may be those who, apparently like Patrick Stewart, are philisophically opposed to a human presense in space, but I'd think there are many more who simply cannot see we bother. It's difficult to explain to them that all humanity has done so far is dip a toe into the ocean that is the universe--and despite the remarkable advances in such areas as communication and navigation that satellites offer, the real rewards of space exploration have yet to be realized: New Worlds upon which to live.

But start talking in those terms to people who are understandably pre-occupied with the details of getting through another day, and you'll likely get a look which says stop wasting my time with science fiction.

Park's question about Mars is a perfect illustration: ...what...could [we] bring back that would begin to compensate for the cost of going to get it. The big picture seems to escape him...it's ultimately not about what we can bring back from Mars, but rather what we can build there.

There was a time, though, when talk of magnetic resonance imaging would have produced that same incredulous look, or when the concept of supersonic flight would have brought a derisive scoff.

The best we can do is to make sure the work doesn't stop...make sure the naysayers don't fulfill their own prophecy by grounding the dreams of the visionaries. Day by day, it's the engineers, the scientists and the technicians who will turn skeptics into believers.