Is there life after the prize? For most winners of NASA's Centennial Challenges, the answer is yes, but not quite as expected.

Challenges can create entire industries, notably the commercial suborbital spaceflight business taking shape out of the Ansari X Prize and Northrop Grumman Lunar Lander X Challenge (see page 57). But often reaping the benefits of winning can entail a longer and less direct route to market.

LaserMotive, winner of the 2009 Power Beaming Challenge, saw its future in laser-powered launch vehicles, but its first market is more down-to-earth—delivering laser power over optical fiber. And the winner of the 2011 Green Flight Challenge, Pipistrel Aircraft, acknowledges its design was impractical, but says it is applying the lessons learned to new products.

It was a NASA competition that led to the formation of Seattle-based LaserMotive. “I had been working for a long time on laser-launch power beaming when I became aware of NASA's Centennial Challenges,” says Jordin Kare, co-founder and chief scientist. When NASA launched its space-elevator challenge, he was approached to participate.

“In 2006 I was approached by an acquaintance with seed money to start a company to develop power-beaming ideas,” he says. “I thought we could start by going after the NASA challenge, as it matched up well with what we were interested in. So we agreed to see what happened at the 2006 challenge, then decide if we would proceed.”

Reviewing results of the first two rounds in 2005 and 2006, Kare decided he could do better. “There was a high probability we would win,” he says. “But it proved more challenging than we originally thought.

“It was such a new technology, it was not obvious what was the right way to go,” says Kare. “With the Astronaut Glove Challenge it was clear what output it would produce, with the Lunar Lander it was pretty clear, but with Power Beaming there probably was not an end product.”

The objective of the Power Beaming Challenge was to demonstrate technology for a space elevator by powering a climber up a cable. Starting at 50 meters (164 ft.) in 2005, the goals increased each year to reach a climbing height of 1 km for the 2008 contest. The first two contests were dominated by spotlights and mirrors reflecting sunlight.

“The first year we competed, 2007, was the first where they increased the height from 50 to 100 meters. That was tough to do with a searchlight,” says Kare. “It was the first time that the best way was a laser. The next year it was 1 km, and nothing but a laser would work.” LaserMotive won the $900,000 Level 1 prize in 2009 by climbing the 1-km cable at 3.8 meters/sec., but never achieved the 5 meters/sec. required to win the $1 million Level 2 prize.

“It was a reasonable path. It got us going with the right kind of technology, the lasers and receivers,” says Tom Nugent, co-founder and CEO. “It was not a detour, but after we won the first challenge the organizers told us there would be an additional round [in 2010]. We started improving the hardware in expectation of another round. Then it was canceled, which cost us six months of time and money.”

To a fledgling company like LaserMotive, the reversal came at a huge cost. But where many entrepreneurs raise cash by winning business-plan competitions, the NASA challenge gave it an opportunity to show its technology in action. “Having hardware demonstrated in the field was so much more valuable than a business plan, and a huge accelerator for us,” says Nugent. The publicity generated by the challenge was also a big benefit.

But winning the challenge did not generate the follow-up from NASA itself that the company had expected. From August 2010 to March 2011, LaserMotive did participate in a beamed-energy propulsion study funded by NASA Glenn Research Center and the U.S. Defense Advanced Research Projects Agency. It showed that a small single-stage-to-orbit (SSTO) laser thermal launch vehicle, called Laser HX, was technically feasible.

“For the first time we got a working design for an SSTO,” says Kare. The concept uses a ground array of 50-kw laser modules to beam 220 megawatts of power to a heat-exchanger panel on the launch vehicle. Hydrogen propellant is pumped through the panel, heated and expelled through a nozzle to produce an efficient propulsion system that can vary its specific impulse from low on takeoff to high in orbit.

Companies including Aerojet, ATK and Lockheed Martin looked at the power-beaming propulsion concept under NASA's Ride the Light study in September 2011. “Everybody said it would work,” says Kare, but there has been no follow-on work. “We are all set to do tests of a microchannel heat exchanger, but there is no money,” he says. Instead, LaserMotive has focused on the unmanned aircraft systems market.

“We had been envisioning UAS as a likely initial market, so as we ramped down from preparing for a second round we started responding to inquiries that were coming in from the military within a week or two of winning the competition,” says Nugent. LaserMotive demonstrated power beaming to a model helicopter in 2010 and later set a record for laser-powered flight by hovering a small quadcopter UAS for almost 12.5 hr. “We turned around pretty quickly to the market we saw,” he says.

“We began seeking follow-on development funds from the military,” says Kare. “People knew about the challenge, and it gave us a certain amount of technical credibility.” This led to work with Lockheed Martin's Skunk Works to power the company's Stalker small UAS by laser—first in the wind tunnel, for 48 hr., then later outdoors over the desert.

The Stalker demonstration beamed 300 watts of laser power to a solar panel under one wing, with a pointing accuracy of 1 cm at 500 meters, producing enough electrical power to keep the batteries charged. An issue prevented a 48-hr. outdoor flight, but “we had positive power to the vehicle,” says Kare, adding “You still need batteries for takeoff and landing, and interruptions such as satellite passages [as high-power laser are not allowed to be pointed at spacecraft].”

Near-term, and a far cry from its laser-launch ambitions, LaserMotive is focusing on the power-over-fiber market. Able to deliver interference-free power, the technology is expected to find application in laboratories, test environments, telecommunications, and medical systems. The company is developing the system as a lighter alternative to copper wire for powering tethered ground or underwater robots, and is demonstrating the first UAV powered over fiber in the laboratory, Kare says.

For Slovenia's Pipistrel, Green Flight was not the first NASA challenge it won. “We first competed in 2007, in the Personal Air Vehicle [PAV] Challenge, with a prototype we had at the time,” says development engineer Tine Tomazic. “It was a way to have the aircraft independently measured for performance, to see where there was room for improvement.”

NASA provided measuring equipment and know-how. “We could not afford such an elaborate testing set-up ourselves,” he says. Pipistrel's Virus light aircraft won by a considerable margin, although “the competition was not that fierce,” he admits.

Pipistrel returned in 2008 to compete in NASA's General Aviation Technology (GAT) Challenge. “The rules were quite a bit different,” says Tomazic. “In 2007 it mattered to have an aircraft that flew the quickest on the least fuel. In 2008, you had to be very quiet in takeoff and climb.” But the company won again—with the same aircraft.

Green Flight was a combination of the two previous competitions, looking for speed, efficiency, range and low noise. “You had to be able to take off and land in a reasonable distance and fly as slowly as a light sport aircraft [LSA], otherwise the focus was more on efficiency at speed,” says Tomazic.

The rules set a threshold of 200 passenger-mi./gal. to qualify for the prize, or the equivalent in energy for electric propulsion, and the result—perhaps unintended—was that “the designs turned out not to be practical, as we all tried to squeeze out as much efficiency as possible,” he says.

“The rules were drawn up to see aircraft on the flight line that resembled light sport aircraft,” says Tomazic. “And the threshold of 200 passenger-mi./gal. was doable with a LSA with a high aspect-ratio wing, retractable gear and electric power,” he says. “But with $10 million in turnover annually, if we were going to invest $2 million in a competition then we wanted to know we would win.” So Pipistrel set out to “smash” the target.

NASA Langley engineer Mark Moore, who drafted the initial rules that emphasized efficiency and speed, says it was never the agency's objective to create a product for the LSA market. “Certainly our prize partner, the CAFE [Comparative Aircraft Flight Efficiency] Foundation, had this interest,” he says. “As CAFE put their interpretation into the rules, it was clear that their priority was more for near-term LSA market feasibility . . . but the original intent was still present.”

With an unconventional four-seat, twin-fuselage configuration, Pipistrel's winning Taurus G4 had a 75-ft. wing span and a 150-kw electric motor. “We did not settle for 200 passenger-mi./gal. and wanted as much as possible,” says Tomazic. “On paper it would do over 500 passenger-mi./gal., and in testing it achieved that, flying in a straight line.”

“The first moment I saw the Pipistrel entry on paper, my reaction was 'That's exactly what I would have done',” says Moore. “To me, their effort showcased exactly the intent: Push aerodynamic efficiency as hard as you can, while realizing that you only have a year to design, develop, build and test-fly a custom one-of-a-kind aircraft.”

NASA was barred from awarding prize money to non-U.S. teams, so Pipistrel partnered with Jack Langelaan, associate professor of aerospace engineering at Pennsylvania State University. “Back-of-the-envelope calculations showed that a modern self-launching sailplane would exceed the minimum criteria by a significant margin, and that the Pipistrel Taurus was a great candidate for modification to compete,” he says.

Langelaan and Tomazic met at a convention in spring 2010. “Because the competition was limited to U.S. teams, they needed me as much as I needed them,” Langelaan says. “And because my group had been doing research on flight planning and control to maximize efficiency, I was able to make a technical contribution.”

The Taurus G4 won, achieving 403.5 passenger-mi./gal. at 107 mph—more than double the threshold. But did winning the $1.35 million prize pay off for Pipistrel? The previous PAV and GAT challenges clearly advanced the company's product plans—it has delivered more than 170 Virus aircraft since 2009 and it remains a best-seller, Tomazic says, but the unique G4 was not practical because of its configuration and size.

“We learned a lot,” he says. The G4 had the largest battery pack ever flown, 10 times larger than the Boeing 787's. “We learned how to manage such a large battery, prevent discharge, handle thermal management and keep everything in balance.” Pipistrel also learned to manage electrical grounding and electromagnetic interference in an all-electric, all-composite aircraft where the largest piece of metal was a 7-lb. engine mount.

Since Green Flight, Penn State has “seen a big jump in interest for electric and hybrid aircraft,” says Langelaan. “Many students in our capstone aircraft design class are working on electric-powered general aviation aircraft . . . [and] we're starting plans to convert a sailplane to an electric aircraft as part of the design course.”

“Thanks to both Pipistrel and the [second-place] University of Stuttgart, breakthrough technologies for efficiency, emissions and noise were showcased, and I believe we achieved an epiphany concerning electric flight,” says Moore. “There is so much more momentum relating to electric flight than two years ago.”

Despite the G4's uniqueness, competing in Green Flight was “directly useful,” says Tomazic. Elements of the design have found their way into the latest version of Pipistrel's two-seat self-launching glider. Although it has a 45-kw motor, and not the G4's 150 kw, “the battery-management electronics are identical,” he says. “Some lessons we will use later, some we will avoid in the future, and that is valuable, too.”