NASA 

National Aeronautics and 

Facts

Space Administration 

Dryden Flight Research Center 

P.O. Box 273

Edwards, California 93523 

Voice 661-276-3449 

FAX 661-276-3566 

pao@dfrc.nasa.gov FS-2004-03-087 DFRC 

Beamed Laser Power For UAVs

Researchers at NASA's Marshall Space Flight Center, 

Huntsville, Ala., and Dryden Flight Research Center, Edwards, 

Calif., and the University of Alabama in Huntsville have 

flight-demonstrated a small-scale aircraft that flies solely by 

means of propulsive power from an invisible, ground-based 

infrared laser. 

Flights of the lightweight, radio-controlled model airplane 

inside a large building at NASA Marshall are believed to be 

the first time that an aircraft has been powered only by laser 

energy. The demonstration was a key step toward the capability to beam power to an aircraft, allowing it to stay in flight 

indefinitely – a concept with potential for the scientific 

community as well as the remote sensing and telecommunications industries. 

During the flight demonstration in September 2003, an 

engineer manually directed the 1 kw laser's energy from a 

central platform at a panel of infrared-sensitive photovoltaic 

cells mounted on the bottom of the aircraft to power its tiny 

six-watt motor as it flew circles inside the building. As a 

precursor to the laser beamed-power flights, a similar demonstration using a large theatrical spotlight was flown in the 

summer of 2002 at NASA Dryden, proving that beamed 

visible light could power the 11-ounce aircraft. The two 

lightweight model aircraft used for these demonstrations 

were designed and built in the NASA Dryden model shop, and 

were controlled using the same over-the-counter radio control instrumentation available to model aircraft hobby enthusiasts. 

Two months after the initial laser-powered flight demonstrations, the team used the same laser system on a rotorcraft 

version that operated along guide wires. Several attempts 

were then made to fly the original aircraft, now modified with 

two motors for additional power, outside on a laser range on 

the U.S. Army's Redstone Arsenal near NASA Marshall. 

These attempts were not successful, due to the aircraft's light 

weight and low power being unable to overcome the effects 

of gusty winds. 

With a laser beam centered on its panel of photovoltaic cells, a

model makes the first flight of an aircraft powered by a laser

beam inside a building at NASA Marshall.

NASA Photo ED03-0249-18. 

History of Power Beaming 

The concept of wireless transmission of electrical energy – 

or power beaming – is not new. The idea has been around for 

decades, proposed primarily for space-based solar farms to 

supply energy to Earth or the surface of another world, or for 

wireless power on Earth. The two technologies that appeared 

suitable for power beaming involved microwave or laser 

energy. 

Researchers in several countries flew a variety of model 

aircraft using beamed microwave energy 20 years ago. However, the nature of the microwave beam causes it to spread out 

with distance, with a commensurate decrease in the power 

delivered to the target. While flight was easy to demonstrate 

at close distances with microwave beaming, flying an airplane 

at long distances would require a prohibitively powerful 

microwave beam to compensate for the energy loss as the 

beam spread. That left only lasers as a potentially viable 

option for practical power beaming. 

1
NASA Dryden's Dave Bushman aims the optics of a laser device 

at a panel of solar cells during the first flight demonstration of an 

aircraft powered by laser light. 

NASA Photo EC03-0249-36. 

Until recently, however, laser technology had not advanced 

to the state where such applications could be possible. A key 

breakthrough to the potential success of power beaming is use 

of a new system of clustered tunable lasers conceived by laser 

scientists at the Lawrence Livermore Laboratory. Clustered 

lasers could provide similar efficiencies as high-power free 

electron lasers, whose development has not yet matured to the 

point of being practical for these applications. 

Power Beaming for Uncrewed Aircraft 

The development of prototype lightweight, solar-electric 

powered remotely operated aircraft such as the PathfinderPlus and Helios Prototype under NASA sponsorship led to a 

renewed interest in laser power beaming. With an adequate 

power alone. 

Although inclement weather poses a severe limitation on 

power beaming to an aircraft, several ground stations could 

be located so that one should be able to beam power while the 

primary site is in the rain. Careful selection of the laser 

wavelength could permit the laser station to compensate for 

atmospheric and weather-related losses. Another possible 

solution would be to beam the power down from a laser 

power station in space that can always see the aircraft above 

the clouds. 

Other Potential Applications 

• High-altitude airships: Beaming power to high-altitude 

airships for the same role as high-altitude, long endurance 

uncrewed airplanes has also been proposed, although the 

technology to allow a dirigible or blimp fly at high altitude 

has yet to be demonstrated. 

• Extra-terrestrial robotic rovers and aircraft: Laser 

power-beaming could energize ground-based robotic rovers 

on the moon and Mars or power a small airplane in the 

Martian atmosphere, with electricity beamed from an orbiting satellite. 

• Small or swarming unmanned aircraft: Small, lowaltitude scout aircraft that could fly guard duty over a military 

combat area, or fly in front of a convoy to warn against an 

ambush could be periodically recharged with a laser beam so 

they could stay aloft as long as needed. 

• Power transmission: In locations where it is not practical 

to run power transmission lines, power beaming could “close 

the gap” by beaming the energy across the open distance. 

Power could even be beamed to a special aircraft or satellite 

that would then send the energy 

power directly to 

system to provide supplemental energy at night when solar 

energy is not available or is minimal at high latitudes in 

winter, a solar-electric aircraft has the potential to be 

able to fly day and night for weeks or possibly months 

without landing. This ability to fly continually would 

be a breakthrough in aviation, with such high-altitude, long-endurance, aircraft able to serve as "atmospheric satellites" on surveillance or telecommunications relay missions. 

Laser power-beaming was considered as one 

option, along with regenerative or non-regenerative fuel cell systems or improved rechargeable 

batteries, to provide supplemental electrical 

energy to power such aircraft. Power beaming 

could help recharge a fuel cell- or batterybased energy storage system on a solar aircraft, and also could provide significantly 

back to Earth a great distance 

away. 

• Space applications: Power 

transmit power from the ground 

to satellites to provide more ensolar panels alone. Space-based solar 

Earth, the moon or other planets. Other 

high-power lasers to "rejuvenate" damaged sodevelopment of "power farms" (satellites with very 

large solar panels) to beam energy to another satellite that 

required periodic high amounts of energy.

more power to a payload than solar 

beaming has been proposed to 

ergy than they could absorb from 

farms could beam 

suggestions include using specially tuned 

lar panels on satellites to extend their life, and 

March, 2004 

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