Researchers at the US Naval Research Laboratory (NRL) are currently developing ‘Solar-Soaring’ technology to provide the unmanned aerial vehicles (UAV) with the ability to fly for more than 12 hours using energy from the atmosphere and sun.
Solar-Soaring is the name given to a pair of endurance-enhancing technologies that help warfighters by enabling an autonomous aircraft to fly for longer periods without the need to carry extra weight in batteries.
NRL Tactical Electronic Warfare Division senior aerospace engineer Dr Dan Edwards said: “One of the common complaints that we hear across industry and the warfighters is that they want aircraft to fly longer.
“One great way to do this is to capture atmospheric wind energy or solar energy to extend the endurance.”
Edwards added: “Sunlight heats up the surface of the Earth, which in turn heats the lowest layer of air.
“That warm air eventually bubbles up as a rising air mass, called a thermal, which the airplane can use to gain altitude. It’s indirectly solar-powered.”
Furthermore, solar power can be harnessed to directly power the drone using solar cells, which are semiconductor devices that help convert light into electricity.
The motor is turned off during soaring and the solar array is able to recharge the on-board battery faster, thereby increasing the unmanned aircraft’s mission availability.
Despite the integration of the new technologies, an aircraft still needs to carry a battery.
However, the battery can be smaller in size as a result of the solar and soaring capabilities on-board the jet.
Edwards noted: “In the case of Solar-Soaring, we’re demonstrating the techniques to fly aircraft with a higher endurance.
“These techniques are portable to a lot of the programmes of record, like the small-size Raven or potentially the larger Predator, so it’s a pretty broad application space.”