Jump-started by contest, power-beaming laser leaps to new applications
Innovation is by its very nature a strange process in which the only certainty is an unpredictable outcome. Take, for instance, the strange case linking the early Russian rocket pioneer Konstantin Tsiolkovsky, with the first outdoor tests this year of a laser-powered aircraft in California.
In 1895, inspired by the sight of the recently erected Eiffel Tower in Paris, Tsiolkovsky conceived the idea of a free-standing tower reaching from the Earth's surface to geostationary orbit. During the 20th century, the idea became better known as the space elevator and by the mid-2000s had sparked sufficient interest forto sponsor a series of Space Elevator Games. Launched as part of the Centennial Challenges program, the games were designed to foster technologies that could one day be used in a space elevator, but which were also applicable to nearer-term NASA programs.
One of the key technologies was the power-beaming system, which transmitted laser energy to the “elevator.” The contest, with a prize of almost $1 million, was won in 2009 by LaserMotive, headquartered in Kent, Wash. The company had been founded just three years earlier by laser propulsion expert Jordin Kare and Tom Nugent, former director of research for LiftPort Group.
LaserMotive clinched the prize by using a complete power-beaming system to propel a robotic climber to a height of 3,280 ft. (1 km) up a tether suspended below a helicopter. Not only was this the longest distance ever achieved for laser power beaming, but it came at the fastest speed of 3.97 meters (13 ft.) per second and with the most power transferred to a receiver: over 1 kw.
Winning the event, held at NASA Dryden Flight Research Center at Edwards AFB, Calif., was LaserMotive's big break, says Nugent. “We were the only team to make it across the finish line—but beyond the prize money, the publicity was huge.” Nugent had been working on the space elevator concept for several years and “reached out” to Kare to help perfect the idea in the run-up to the contest. “It was a convenient focal point, and provided a trigger for what happened after,” says Kare.
Despite his longtime enthusiasm for the novel transport concept, Nugent says he reluctantly “came to the conclusion that a space elevator is not going to be built on Earth in my lifetime. However, there are other applications for this wireless power via laser technology.” One of these is beaming power directly to UAVs, a role that is currently being tested with theSkunk Works somewhere in the desert Southwest U.S.
Under the tests, LaserMotive fed laser power to a small Stalker UAV fitted with a lightweight photovoltaic receiver and onboard power management system. The evaluation demonstrated net positive power in flight at ranges up to 600 meters. The addition of the laser receiver did not impact its normal flight operations or aerodynamics during the tests, which were conducted over different conditions at day and night. LaserMotive says the beam director tracked the receiver for long periods, with centimeter accuracy at 500 meters, despite turbulence and aircraft maneuvers.
More than 90% of the company's annual revenues go toward R&D, while the split between basic and product-related research spending is more equally divided. “For us, in a sense, we are creating a new market and by doing that we're trying to decide who will be the first customer. But on the flip side, for defining something for a specific customer, there is more basic R&D going on,” says Nugent. As a smaller company, LaserMotive must also leverage “a whole bunch of other [academic and industry] fundamental R&D, particularly in laser technology,” adds Kare.
The rate of innovation “could go even faster” if there were broader awareness of the technology around the industry as a whole. “The problem is getting the market to understand what this new capability can do for them,” says Nugent.
Still, Nugent sees a slow revival in the creativity climate. For the last 30 years, innovation has been stifled in the space and advanced military technology arenas by a fixation on large, long-term projects, he says. “This forced the industry into a mode of operating that was not as innovative, or not so attractive to work in.” However, over the past decade, the climate has started to change with the emergence of near-space and other markets. “There's a whole new generation of startups that really are bringing technology in from other areas and reapplying that in an innovative way to the aerospace world.”
One of LaserMotive's biggest challenges is to “say this technology—wireless power—is real, and it's here today. That's why we've been lucky to work with Lockheed Martin's Skunk Works with this demonstration on Stalker,” says Nugent. “People at trade shows say they've been watching us. So people in large and small companies at least have a notion that this technology is important. But we have very few that are willing to take the next step.”