NASA - National Aeronautics and Space Administration

NASA and the Spaceward Foundation awarded a prize of $900,000 to LaserMotive LLC of Seattle, Washington for their winning performance in the Power Beaming Challenge competition held on Nov. 4th through 6th at the NASA Dryden Flight Research Center. The Spaceward Foundation of Mountain View, CA manages this competition for NASA’s Centennial Challenges Program. › View image gallery

LaserMotive climber about to reach the top bumper at 1 kilometer (object on cable below flags).
The Power Beaming Challenge is a demonstration of wireless power transmission in which teams build and demonstrate systems to beam energy from the ground to a robotic device that climbs a vertical cable. To compete, teams must integrate a complex set of technical skills for optical beam forming, electro-mechanical beam tracking, photovoltaic beam conversion, power capture electronics, and mechanical drive. To win a prize, the climber must reach the top of the cable at a height of one kilometer. Teams that can reach the top share in the prize purse of $2,000,000 based on their vertical speed and payload mass. LaserMotive’s average speed on their best of several successful climbs was 3.9 meters per second and by exceeding the average speed of 2 meters per second and being the only team to reach the top, they claimed the entire $900,000 prize for that level. Teams had to exceed an average speed of 5 meters per second to qualify for a share of the remaining prize purse of $1,100,000. That amount will remain available for the next Power Beaming competition.

NASA is interested in power-beaming technology for a variety of purposes including remotely powering rovers and instruments on the Moon. On Earth, the technology might supply communities with power following natural disasters. There are also some intriguing applications for power beaming for airships, satellites and space transportation, including the space elevator concept.

LaserMotive was competing with two other teams, the Kansas City Space Pirates and USST and although they did not post prize-winning performances, the other teams kept the contest outcome in doubt up until the final moments. Over the three days of competition, each team had three operational windows of 45 minutes in which to make as many climbs as possible. In their window, the KC Space Pirates did successfully climb to about 50 meters short of the target and looked like a very strong contender with their climber named “MaryAnn” (The Space Pirates have a number of different climbers and have named them after characters from the Gilligan’s Island TV show.) MaryAnn’s mass was 1.28 kg.

On LaserMotive’s first turn they were quickly successful. Their climber names “Otis” (reference to the elevator company) reached the top in 4 minutes and 2 seconds and then repeated the climb in 4:01. That speed was enough to exceed the 2-meters/sec requirement to qualify for a share of the first-level prize of $900,000. The mass of Otis was 5.22 kg. The second day of the competition began with the first turn for USST. They did achieve a brief climb but had several technical problems. The mass of the USST climber was 8.88 kg.

Laser Motive was up next and improved their score with climbs of 3:50 and then 3:48, which would prove to be the best of the competition but not enough to break the 5 meters/second barrier. Their best time represents a speed of 3.95 meters per second (8.8 mph).

USST decided to forfeit their second turn as they continued to work on technical problems. The KC Space Pirates did makes some climbs on their second turn but continued to have difficulties and did not reach the top.

On the third day, each team had one more chance. USST was up first and despite the corrections that they had attempted, their system still could not climb to the top and they were done. LaserMotive decided to take a risk on their final attempt. They stripped structural weight from “Otis” (from 5.22 kg to 4.34 kg), leaving the delicate solar panels more exposed to potential damage during takeoff and recovery. They hoped to exceed the 5 meters/sec speed and they might possibly have done that except for one technical glitch. The climber starts off sitting on a bumper that is clamped to the lower end of the cable. The LaserMotive climber got stuck to the bumper and when it began to climb it dragged the bumper with it for about 25 meters. Even with the added resistance the climber made progress and then shot away when it was free of the bumper. However, it did not make it to the top.

The KC Space Pirates had the last operating window of the competition and began with high expectations. They first tried with “MaryAnn’ and had climbs of several minutes but did not reach the top. Then they switched climbers to a model called “Skipper” which made a long climb of about 12 minutes duration but at a fairly slow rate and their attempt again ended about 50 meters short of the top.

Ben Shelef of the Spaceward Foundation said, “I have watched these teams steadily improve their designs since we began the challenge in 2005 and the sophistication of the systems that they demonstrated this week is impressive by any standard.”

The previous Power Beaming competition in 2007 had been conducted with a crane supporting a 100-meter high cable and no team was able to reach that much lower target in the required time. So the performance of all of the teams this year was a major step forward. The challenge requirements were far more demanding and the operating environment was far more complex. The teams and the Spaceward crew had to contend with helicopter operating times limited by refueling needs, laser operating windows constrained by satellite passages and unpredictable holds dictated by unrelated airfield operations, not to mention desert winds and shorter periods of daylight. The support and coordination provided by the NASA Dryden Flight Research Center personnel was essential to operational success.

A vertical “racetrack” was created for the competition by suspending a cable from a helicopter flying 1,300 meters (4,300 feet) overhead. This arrangement, along with the high-power laser systems provided a unique and unprecedented testing environment. According to Centennial Challenge program manager, Andrew Petro, “The kilometer-high vertical cable system established for this competition was something that had never been done before and it is a remarkable accomplishment in itself. The Spaceward Foundation and their partners along with our hosts at NASA Dryden deserve a lot of credit for their creativity and determination.

The precise flying was the work of pilot Doug Uttecht, in an MD-530FF from Northwest Helicopter of Olympia, Washington. Keith Mackey, an aviation consultant from Ocala, Florida developed the navigation techniques and provided guidance from the ground via radio. Ensuring that the cable did not snag and that each climber was picked up and deposited back to Earth gently was the job of the “Tetherman”, Michael Keating. Michael is a Spaceward Foundation volunteer and a high school physics teacher in Pasadena, California. Doug, Keith and Michael performed flawlessly and no climbers were damaged during numerous launches and recoveries.

The Power Beaming Challenge is one of six Centennial Challenges managed by NASA's Innovative Partnership Program. NASA's Centennial Challenges program's goals are to drive progress in aerospace technology that is of value to NASA's missions; encourage participation by independent inventors, student groups and private companies of all sizes in aerospace research and development; and find innovative solutions to technical challenges through competition and cooperation.

Official results of the Power Beaming Challenge, as well as video and photography, are available at: http://www.nasa.gov/offices/ipp/innovation_incubator/cc_home.html