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Space elevator faces reality

Pat Rawling / NASA
An artist's concept shows a space elevator stretching down from orbit.

Like almost everyone else in the space vision business, the enthusiasts who foresee a "railway to space" are adjusting their high-flying dreams to fit down-to-earth realities.

"We don't have all the questions, let alone all the answers," Michael Laine, head of the LiftPort Group, told an audience of about 50 people on Saturday during the 2009 Space Elevator Conference on Microsoft's campus in Redmond, Wash. (Microsoft is a partner in the msnbc.com joint venture.)

Laine probably knows as well as anyone how few answers are available.

LiftPort's Web site is still counting down toward his goal of putting a real live space elevator into operation by 2031. But Laine's years-long quest to turn the concept into an actual business left him hundreds of thousands of dollars in debt by 2007, with a legal cloud hanging over his head.

Laine put LiftPort into mothballs and lay low for two years, spending part of that time in the International Space University's study program. It's only been in the past few months that he's been able to lift his head above the clouds again. "We went through some difficult times," he wrote last month in a newsletter, "but are beginning to get all those issues settled to the point where LiftPort will rise again (pun intended)."

Laine told me today that his legal troubles are "kind of in a strange point of limbo," and that he's still massively in debt. But he has enough hope for future ventures that he's willing to get back into the space elevator game rather than moving on to more conventional business ventures.

"I'm actually really happy to be back out there," he said.

Still a laughable idea?
The space elevator concept is one of the highest-flying ideas out there: Imagine a super-strong tether swinging out, say, 100,000 miles from Earth's surface, with laser-powered robots shuttling up and down from a ground- or sea-based station to an orbital platform. If such a thing could be built, the idea's proponents say the system could cut the cost of putting cargo into space from $10,000 to $100 per pound.

The idea is at least a century old - and was most famously popularized by science-fiction guru Arthur C. Clarke, who once said the space elevator would succeed "50 years after everyone has stopped laughing."

At last year's Space Elevator Conference, pioneer researcher Bradley Edwards said the first elevator could be built within 15 years, at a cost of $7 billion to $10 billion. The speakers at this year's conference took a far more sober view of the financial and technical resources that would be required. "They're not the rosy numbers that you hear," said Ben Shelef of the Spaceward Foundation, who manages two NASA-backed contests for space elevator technologies.

In a technical paper presented at the conference, Shelef concludes that the conditions required for a working space elevator are "actually very difficult to satisfy" at any price. That's the bad news. The good news is that the technologies needed for a theoretical space elevator project could well lead to payoffs - even if the elevator itself never gets built.

Those technologies fall into three categories:

Super-light, super-strong materials
The biggest piece of the space elevator system would have to be a tether strong enough to stretch for tens of thousands of miles, passing through Earth's rough weather and the radiation-pounded space environment. NASA's $2 million Strong Tether Challenge is aimed at rewarding the breakthrough development of lightweight materials that are twice as strong as the current industry standard.

Ted Semon
After being put to the test, a Japanese-made carbon nanotube tether looks like a stretched piece of videotape.

During this year's conference, a Japanese-American team tried to win the challenge with a tether made out of carbon nanotube strands. The tether looked and felt like the videotape from an old VCR cassette, as described on Ted Semon's Space Elevator Blog.

The nanotube tether didn't match the strength of its industry-standard competitor, known as the "house tether" - and that means NASA's prize has gone unwon for another year. But Shelef said the contest is still fulfilling its goal of promoting materials research that goes "beyond the leading edge."

He said the materials developed for the competition could conceivably be used in super-strong parachutes for NASA's Mars landings, or better carbon composites for spacecraft, airplanes and automobiles.

Power-beaming systems
Another NASA challenge offers $2 million in prizes for beam-powered robots that can scuttle quickly up a fabric ribbon - sort of like the robotic climbers that would make their way up the thousands of miles of a space elevator's tether.

The Power Beaming Challenge's bar has been raised every year over the past three years. To win any money in this year's contest, a team would have to send its climber up a kilometer-long (0.6-mile-long) tether stretched between the ground and a hovering helicopter, at an average rate of at least 2 meters (6.6 feet) per second.

"Think about Batman shooting his little dart arrow and going up," Shelef said. "He's going about 2 meters per second."

Europe's EADS group has tested laser-powered rover prototypes.

Three teams - the Kansas City Space Pirates, Seattle-based LaserMotive and the University of Saskatchewan Space Design Team - have devised laser-powered systems to meet the challenge. They're all likely to go for the gold during a contest tentatively planned for October at NASA's Dryden Research Center in California's Mojave Desert.

"This is like military-grade stuff," Shelef said. "They're doing work on the level of military contracts."

Even if robotic climbers are never beamed up an actual space elevator, the resulting technology could be used to power rovers operating in the icy, sunless depths of craters at the moon's south pole, Shelef said. He didn't mention the potential military applications, but if you watch video of the laser-beam tests, you could easily imagine infrared laser systems capable of tracking or disrupting aerial targets.

High-flying platforms
Another piece of the space elevator puzzle involves building aerial platforms that would serve as way stations for those robotic climbers. In the past, LiftPort's Laine has focused on balloon-lofted platforms that could serve as weather monitoring stations or telecommunications relays - and he said he's hoping to revive the balloon venture, perhaps as part of a military research program.

Others are working to build different kinds of platforms for spreading the space elevator gospel: academic programs that would back research into elevator-centric engineering issues, for example, or a peer-reviewed journal that would publish such research. The talk at this year's conference was that Canada's McGill University would soon be raising its research profile.

"We need to partner with everyone we can," said Semon, who does his part as the president of the recently formed International Space Elevator Consortium as well as a leading blogger following the field.

Should NASA be offering millions of dollars to support technologies for a space elevator that may never be built, at the same time that it's apparently falling billions of dollars short in its drive to re-energize space exploration? Shelef and his colleagues are under no illusion that they'll come up with the next giant leap into space anytime soon. For now, they're content with the small steps being encouraged by NASA's prize program.

"At this budget level, it can't hurt," Shelef told me. "It can only give you a good answer."

Update for 10:15 p.m. ET: Personal Spaceflight's Jeff Foust, who attended the weekend space elevator conference, passes along word that Armadillo Aerospace plans to take aim at NASA's $1 million top prize in the Northrop Grumman Lunar Lander Challenge during Labor Day weekend. The timing for the prize attempt is mentioned on The Space Fellowship's Armadillo discussion forum. Armadillo won a $350,000 prize last year for a less ambitious flight.

More about the space elevator concept:

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