When the contest was held last October, none of the eight entrants made it all the way up the ribbon. But Mr. Jones's Snowstar machine traveled farthest, all of 20 feet. The hexagonal array of solar cells, powering two pairs of rollers that shimmied up the ribbon, was judged Most Likely to Win in the 2006 challenge, set for August. The prize has been increased to $250,000 this year, from $50,000. To win, the climbers must make it up the ribbon in less than a minute. So far, 19 teams have signed up, nearly twice as many as in 2005.

Another well-known high-tech contest, the Darpa Grand Challenge, also had disappointing results when it started in 2004. The all-robot off-road rally, sponsored by the Pentagon's fringe science arm, the Defense Advanced Research Projects Agency, or Darpa, attracted dozens of competitors. But none of the vehicles made it past the seventh mile of the 150-mile course, largely because of navigation problems.

A year later, five unmanned cars crossed the finish line. That included robots from leading universities like Stanford and Carnegie Mellon as well as one from the Gray Insurance Company, which had no experience in robotics but whose owners had a personal interest in the competition. The Gray team was one of the last to enter the contest, and it had a major setback when Hurricane Katrina wrecked its New Orleans workshop.

Nevertheless, it beat out vehicles built by leading computer-science researchers and backed by defense contractors. It did so well that it has pulled some employees from the insurance side of the business, allowing them to focus on the company's new venture: robotic cars for the military and other entities.

"I never thought I'd work in defense," said Paul Trepagnier, a software development manager at Gray. "I'm a Tom Clancy fan. But that's the extent. I mean, I'm just a programmer in an insurance company."

Many of NASA's contests also center on robotics. The Telerobotic Construction Challenge, scheduled for August 2007, requires a team of machines to assemble items with minimal human supervision. The idea is to let robots, instead of astronauts, build shelters and machinery on the moon and Mars. In the Regolith Excavation Challenge, set for May 2007, an autonomous machine will have to dig through 24 square meters of simulated moon rock. A separate Regolith Oxygen competition, scheduled for 2008, will be held for robots that can extract oxygen from the stones. Some contests will be held annually; others will be one-time events.

NASA funds robotics research through conventional contracts too, and it uses Small Business Innovation Research grants to back companies outside the industry's mainstream. But the paperwork involved in the innovation research grants, called S.B.I.R.'s, can be intimidating.