Standing knee-deep in prairie grass half an hour from the nearest paved road, Kathleen McNamara held one side of a gigantic kite while another researcher stood 20 feet away to support the other wing.
They were waiting for a gust of wind, which usually doesn’t take this long on a hilltop in the middle of Osage County.
“Come on,” McNamara said, growing frustrated early Tuesday afternoon. “This is Oklahoma!”
The state happens to have wind patterns remarkably similar to Japan’s. And that is one reason why Toyota has teamed up with researchers from Oklahoma State University to build high-altitude kites. Of course, the company also wanted to take advantage of OSU’s highly respected engineering and aerospace programs.
Toyota hopes someday, perhaps by the middle of this century, to turn kites into a viable power source. The ultimate goal would be a kite the size of an airliner, big enough to carry solar panels or a wind turbine and send electricity back to the ground.
For now, however, the team is trying to set a new world record for altitude. No kite has ever flown higher than 16,009 feet, reached on Sept. 23, 2014, in Australia.
The OSU engineers hoped to reach 16,500 feet — or 3.125 miles — Tuesday.
“A lot will have to go right for that to happen,” said Ben Loh, an OSU research engineer. “We need the right design, the right equipment and the right wind.”
The OSU team, with Toyota’s help, has spent two years designing and building high-altitude kites while experimenting with different lightweight materials and aerodynamic configurations. The kites tested Tuesday represented the eighth generation of the team’s work, with the newest kites measuring nearly four times bigger than the first generation.
“The important thing is that we’re learning a lot and improving the technology of high-altitude kites,” said McNamara, another OSU research engineer. “Setting a new world record would just be the cherry on top, but it’s not really what the program is all about.”
The team had already given up on one kite Tuesday morning, when low wind speeds wouldn’t take it more than a few hundred feet off the ground. That design included an inflatable polyurethane bladder, which would help keep it stable at high altitudes but increased drag near the ground. To try again Tuesday afternoon, the team switched to a more conventional double delta conyne design.
“It’s basically a scaled-up version of a kite that you would buy off the shelf,” McNamara said. Albeit this kite was constructed from exotic lightweight materials, weighing less than 5 pounds despite covering more than 86 square feet.
It took three tries, struggling to catch sporadic gusts of wind, to get the second kite airborne. Then it climbed steadily toward 3,000 feet until it became just speck in the sky while researchers let out more and more string from a custom-built winch, featuring a complex set of pulleys and electric motors.
Suddenly, the string snapped. And the kite flew away across the prairie, eventually crashing about 4 miles south of the launch site.
The world record attempt would have to wait for another day. In the meantime, the OSU scientists will be analyzing data to see what caused the mishap.
“It’s not a failure if we learn something,” McNamara said. “That’s just the way science works.”