If you think the concept of a space elevator sounds crazy, then the people most actively exploring the idea want you.

They want to hear why you think it’s laughable to try to build a 62,000-mile ribbon straight up from the Equator to ferry cargo into space without need of messy (and dangerous) rockets. They want to hear every single cavil, qualm and conceptual conundrum you might want to raise.

That was the clear message of the second international conference on the space elevator, jointly sponsored by Los Alamos National Laboratory and the Institute for Scientific Research, held this weekend in Santa Fe.

Active dissent was welcomed. The key figures in the space elevator movement, led by Brad Edwards, a former Los Alamos researcher who literally wrote the book on the concept, embrace a big-tent philosophy for moving toward a decision, two or three years down the road, on whether a space elevator might make practical sense.

As of now, it’s only a baby step beyond a simple thought experiment and fodder for science-fiction novels like Arthur C. Clarke’s The Fountains of Paradise. But it does not seem nearly so distant as it once did.

“I’m 86 now, so in 20 years I’ll only be 106, so maybe I’ll live to see it,” Clarke said to the conference by satellite hookup from his home in Sri Lanka.

Clarke emphasized that huge technical hurdles remain, most especially the large amount of space debris that would inevitably collide with the ribbon. But he also encouraged people to see the space elevator concept as a huge leap forward for mankind, one that could provide us with reliable and relatively cheap access to space and transform our sense of the possible in ways we cannot even imagine. Or, at least, he cannot even imagine.

“Really, what you’re asking me is like what you’d ask an intelligent fish, if you asked what would it be like if you moved out into this new medium, air? ” he said.

But as much excitement as there was about Clarke’s virtual appearance to open the conference, a decidedly practical spirit dominated the proceedings. As some of the presenters told the conference, radical advances over the past few years in the construction of carbon nanotubes have suddenly filled in a crucial blank: What material might be used to build a very durable, lightweight tether?

An effort is underway to build a virtual community interested in the space elevator, so people can exchange ideas, kick around solutions to the many engineering problems that would have to be conquered, and generally make progress toward a better understanding of what might be involved in actually building it.

Naysayers were also given time in Santa Fe. In fact, some were all but rushed to the podium. Jordan T. Kare, who spent 11 years at the Lawrence Livermore National Laboratory and now has his own consulting outfit, called out several times in an abrasive voice during a talk on the possible economics of space elevator construction. Since it was all guesswork, trying to gauge how the market for lifting materials into space would evolve if it suddenly became much more affordable, Kare’s frustration seemed both understandable and pointless. But, nevertheless, time was made a day later for him to address the conference — and urge caution on not overstating what space elevators can do.

Andrew Price, a space elevator enthusiast who lives in Hope, British Columbia, was also added to the schedule, and despite the lack of preparation time gave a talk on his idea of a “Frankenstein’s Elevator,” triggering a robust discussion. His idea is to piece together an ugly, rudimentary space elevator ribbon in space, which could be used to build other elevators. That’s in contrast to Edwards’ vision of initially unspooling a simple ribbon, and then using climbers to build it up to adequate strength.

The point was: Think big, think ahead, and listen closely when people start shooting down your ideas. Whether it will take another 20 years, or another 30, to get an operational space elevator in place, no one at the conference claimed to know. But so what? The idea was simply to get a lot of people thinking hard about the idea so that when and if it becomes feasible, we will be ready.

“It will be built about 10 years after everybody stops laughing,” Clarke said at the start of the conference, updating a famous formulation of his from years ago. “And they’ve stopped laughing.”

Not quite. Plenty still chortle at the idea. But to a lot of people, the more you study it, the better it looks.

More here.