LOS ANGELES - A technical issue with a helicopter cable system is forcing the Spaceward Foundation to postpone the Space Elevator Power Beaming Challenge Games originally scheduled for this summer at NASA's Dryden Flight Research Center.

The Spaceward Foundation, which conducts the competition as part of NASA's Centennial Challenges program, together with NASA, which is providing the $2 million prize money for this segment, said the problems cropped up during tests of the helicopter-mounted cable system last week.

"Technical problems were encountered that will require further analysis and additional testing before the competition can be held. The challenge will be rescheduled when the Spaceward Foundation and NASA are confident that these problems have been resolved," the two parties said in a statement.

The space elevator is a revolutionary concept aimed at transporting material into space via a tether, or cable, rather than by conventional rockets. Vehicles would travel along the fixed tether, which would be anchored at one end to the Earth's surface and reach out at the other to a counter-mass in space beyond geostationary orbit.

The contest was established in 2005 in an attempt to speed up development of the Space Elevator concept in much the same way as the Ansari X-Prize was set up to stimulate space tourism. After recent years aimed at proving basic concepts, the challenge this year requires teams to demonstrate devices that can climb a one-kilometer vertical cable using electrical power transmitted via a laser.

The 3/16th inch thick steel cable is suspended beneath an Aris Helicopters-operated Sikorsky S-58T, but issues reoccurred with the winch and pulley system similar to those which earlier this month forced organizers to reschedule the contest to Aug. 5-7. In the latest tests over the dry lakebed at Edwards Air Force Base last week, as the helicopter was hovering above the anchor point, one of the safety release mechanisms gave way unexpectedly. The release mechanism is designed to drop the cable should the pull strength exceed 3,500 pounds, but officials say that according to strain gauges the pull tension was "nowhere near 3,500 pounds."

Spaceward, which is trying to develop a stable racetrack for the contests to use, now plans to re-examine this system and determine what changes may need to be made. Officials believe the games may be rescheduled for September or October, given the time required for reruns of the tests with the teams and the helicopter.

Artist's concept of Space Elevator: NASA