If the drone is provided with a constant influx of energy, he can fly almost forever, until the parts are worn out or an accident. But just a multiple increase in the flight time is interesting to the military – DARPA is testing the concept of recharging the batteries of the drone, firing it with a laser. As a testing platform, the Silent Falcon model was chosen.
The idea is simple, you need to place solar panels not only on the upper side of the wing of the aircraft type aircraft, but also on the bottom. In a broad sense, laser light, as a source of energy, differs little from sunlight. And if we can catch the light of the Sun with one set of panels, then the second one will become the target for the ground laser, which in this way will transfer an unlimited amount of energy there. The main thing is to select radiation parameters that do not destroy the target.
Preliminary calculations by DARPA engineers showed a theoretical possibility to recharge the drone with a laser at a distance of up to 10 km. However, this is in ideal conditions, and target shooting in fog, snowfall or strong winds significantly reduces the effectiveness of the procedure. Worse still, the power of the laser presents some danger for outside purposes if the shot passes by. There is no exact information, but in the first experiments to shoot at once to the sky the Americans were afraid, instead they will force the drone to turn circles around the hill on which the laser will be put.
What will come out of this venture, we will soon find out. Or we will not know, because in case of success the technology will certainly try to hide in the interests of the military. Although civil it would be useful much more – how many low-power multicopters could just hang over gas stations at high altitude, and not decrease, creating a risk for others. And in general, the laser transmission system for urban infrastructure and the Internet of things seems to be a tempting technology for the future.