SAN FRANCISCO — For decades, space enthusiasts have promised that rockets and satellites powered by distant lasers could dramatically reduce the cost of space transportation. While demonstrations of that capability are still years away, LaserMotive Inc. of Kent, Wash., has established a commercial business offering near-term applications of power-beaming technology.
Since sending a robot nearly one kilometer up a cable to win the $900,000 grand prize in NASA’s 2009 Power Beaming Challenge, LaserMotive has shown that its technology can be applied to unmanned aircraft. In October 2010, LaserMotive used power transferred by laser to keep a small unmanned helicopter aloft for more than 12 hours at the Future of Flight Aviation Center, a large indoor facility in Mukilteo, Wash. Company officials are drafting plans to show how laser power can be used outdoors to extend the flight of a fixed-wing unmanned aircraft, LaserMotive President Tom Nugent said.
These demonstrations are designed to show that power beaming is feasible. “We want to keep expanding the performance envelope so one day, 10 years or so from now, we will be able to do power transfer from space,” Nugent said.
NASA has taken notice of that potential. On Sept. 16, the space agency’s Office of the Chief Technologist announced that LaserMotive was one of eight groups selected to receive funding from its Game Changing Technology division to study ways of providing external power to aerospace vehicles using commercially available energy sources. In addition to LaserMotive, the teams selected for the NASA program, known as Ride the Light, are led by: Teledyne Brown Engineering in Huntsville, Ala.; Aerojet in Redmond, Wash.; Alliant Techsystems in Ronkonkoma, N.Y.; Carnegie Mellon University in Pittsburgh; NASA’s Jet Propulsion Laboratory in Pasadena, Calif.; and a Los Angeles-based group that includes Teledyne Scientific, Boeing and the Aerospace Corp.
LaserMotive Inc. at a Glance
Top Official: Tom Nugent, President
Location: Kent, Wash.
Employees: 10 full-time and part-time
Mission: To commercialize wireless power transfer using lasers
Advanced power-beaming technology has many space applications, Nugent said, from offering a ground-based energy source for satellites in low Earth orbit to improving the performance and reducing the cost of rockets. LaserMotive engineers are exploring the potential for a high-intensity, ground-based laser to transfer energy to a rocket’s on-board heat exchanger. By continuously illuminating that heat exchanger, the laser would heat the rocket’s on-board propellant and force the gas out of a nozzle to create thrust. The result would be a clean-burning, high-performance rocket that relies on a ground-based, reusable power source, Nugent said.
Ground-based lasers also could be used to reduce the weight of satellites because the spacecraft would no longer need to carry batteries to provide power when the Earth blocks the sun’s rays from reaching its solar panels, Nugent said. Similarly, space-based lasers could be used to send power from one spacecraft to another, enabling a group of satellites to perform separate functions of a common mission or creating a space-based power plant to distribute power to smaller spacecraft, he added.
The greater the distance between the power source and the receiver, the more difficult it becomes to transmit power efficiently. In addition, costs are expected to rise as the amount of power required increases. A demonstration of the technology that would allow a ground-based laser to send power to a satellite in low Earth orbit could be conducted in roughly five years, Nugent said. It may take one to two decades to send a rocket into orbit using power-beaming alone, he added.
“There is no doubt that the technology can go out many kilometers relatively easily at this point,” Nugent said. “It’s simply a matter of time before we are transferring large amounts of power by laser to orbit.”
Because of that extended timeline, LaserMotive is continuing to explore various terrestrial applications of power beaming technology. That approach has attracted investors from the Space Angels Network, an organization based in San Francisco that links investors with fledgling aerospace firms. “What Space Angels Network investors are looking for is not only exciting space business plans but a solid near-term market,” Joe Landon, Space Angels Network managing director, said. “LaserMotive has interesting technology with potential space applications and they are already working with unmanned aerial vehicle companies.”
On Sept. 21, the Space Angels Network announced that one of its members, Brad Fleury, director of Edge Consulting of San Clemente, Calif., was leading an investment in LaserMotive. Nugent and the Space Angels Network declined to disclose the amount of money invested.
LaserMotive engineers also are exploring ways their technology could be used to transmit laser power through fiber-optic cables. “We have been developing a tethered multi-rotor helicopter platform that receives laser power from the ground over a fiber-optic cable,” Nugent said. “This approach has the advantage of eliminating all the laser safety concerns because the light is always within the fiber enclosure.” That helicopter could be used as a very tall surveillance or communications tower. It would be compact, lightweight and easy to raise to a height of 100 meters, he said.
At the same time, LaserMotive is addressing the laser safety concerns related to its wireless power transfer technology. To prevent the lasers from interfering with commercial aviation, company officials are developing a multilayered safety system to turn off the laser beam if it moves off its intended receiver or if anything approaches the laser beam. “The laser would shut off until its path to the receiver is clear again,” Nugent said. “That will be a crucial part of making this technology fully compatible with aviation.”