Published online 19 October 2007 | Nature | doi:10.1038/news.2007.180
Updated online: 22 October 2007

News

Space elevators: going up?

Competition could pave the way for space technologies.

The USST climber: laser powered.spaceelevatorblog.com

Hold the doors please: teams are scrambling in Utah this weekend to prove that their technologies are the best if you want to get to space in an elevator. The 2007 Space Elevator Games will take place at the Davis County Event Center, after a week of frenetic preparations and qualifying rounds hampered by rain and high winds.

The idea of a space elevator is to allow cheap and easy transport of supplies and people to and from a station (or space hotel) in orbit around Earth. The idea has been around for decades, but the technologies needed to support it have yet to be created.

To promote development, the California-based non-profit Spaceward Foundation has hosted an annual competition since 2005, supported by a cash prize from NASA. Competing teams don't have to build an actual elevator, but instead aim to build a super-strong tether (similar to what would be needed to support a real elevator), or get a robot to climb a suspended ribbon.

Even though previous games have failed to produce a winner (see Space elevator stuck at ground level), this year the competition has been made tougher than ever. But the stakes are higher too: NASA has increased the prize pot for both the climber competition and the tether to $500,000 each, from $200,000 each last year.

Social climbing

In the robot climber competition, teams have to get their device to hurtle up a 100-metre-long ribbon, suspended from a crane, at an average speed of two metres per second. That's a step up from last year's goal of climbing a 60-metre-long ribbon at one metre per second.

The climber must be powered from the ground: strategies include reflecting sunlight from huge mirrors on the ground to solar panels on the climber; shining lasers from the ground up to similar panels on the robot; or firing microwaves up at the climber.

Ted Semon, author of the Spaceward Foundation's official space elevator games blog, says that at least four of the returning teams have improved their power delivery significantly during the past year. “They know what they’re in for,” he says.

“The call for a harder competition this year, in retrospect, was very good,” says Ben Shelef, chief executive of the Spaceward Foundation. He too has been impressed by returning teams: “They have advanced a lot faster than we have made the competition harder.”

Down to four

Qualifying rounds have been taking place all week, although high winds and rain have caused delays. Four out of eight teams have made it into the finals.

The Kansas City Space Pirates, with their solar-powered climber, were one of the first teams to qualify, and their test run went "spectacularly" says Shelef.

Last year’s closest contenders, the University of Saskatchewan Space Design Team (USST), also qualified. They are one of the hot favourites to win this year, and have upgraded from solar to laser power for this year's attempt. "I'm very confident," says Clayton Ruszkowski, USST team leader. They have a wireless communication system between the lasers on the ground and the climber, which should keep the laser optimally aimed as the climber ascends.

The two other teams to qualify are the University of British Colombia's Snowstar, with another solar-powered climber, and a team called Technology Tycoons from Westmont High School.

One on one

Only two teams are aiming this year for the tether competition, the winner of which needs to be at least 50% better than last year's best effort.

The entrants have to produce a loop of material at least 2 metres in circumference and weighing less than 2 grams. This is then stretched to breaking point, and has to outlast a standard tether made from state-of-the-art material (and not subject to the competition size and weight restrictions).

Stephen Steiner, who leads one of the entries, from the Massachusetts Institute of Technology, says he is taking an academic attitude to the games. The MIT tether is the first ever entry to be made entirely of carbon nanotubes — touted as the most promising material to make a rope strong and light enough to reach space. “We know that our materials cannot win this year,” he says, but predicts that by 2010 carbon nanotube fibres will be up to the job.

The games are set to conclude on Sunday, although bad weather may push this to Monday. Semon is confident that one of the teams will walk away much better off than when they arrived: “I think we’re actually going to award some prize money this year,” he says. 

Read about the games as they happen over the weekend on their blog.

Updated:

As of Sunday night, the Space Elevator Games had yet to produce a winner. There’s still one more day of competition for the climber test, so there may yet be a winner for that. But no one will take home a tether prize: MIT’s carbon nanotube tether snapped almost immediately, and the only other contender withdrew at the last minute.

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