The Stalker Unmanned Aerial System (UAS), developed by aerospace company Lockheed Martin, has been kept in the air for 48 hours using a radical new laser power system during trials.
This increase in flight time represents an improvement of 2,400 per cent and could eventually keep military spy drones in the sky forever, the developers said.
The small, silent UAS is already used by Special Operations Forces since 2006 to perform intelligence, surveillance and reconnaissance missions.
"We're pleased with the results of this test. Laser power holds real promise in extending the capabilities of Stalker," Tom Koonce, programme manager at Lockheed Martin Skunk Works Stalker said.
"A ground-to-air recharging system like this allows us to provide practically unlimited flight endurance to extend and expand the mission profiles that the Stalker vehicle can fulfill," he added.
The Stalker UAS was modified for the indoor flight test to incorporate the power beaming technology from LaserMotive.
It makes it possible to wirelessly transfer energy over long distances using laser light.
"This test is one of the final steps in bringing laser-powered flight to the field. By enabling in-flight recharging, this system will ultimately extend capabilities, improve endurance and enable new missions for electric aircraft," said Tom Nugent, president of LaserMotive.
"The next step in proving the reality of this technology is to demonstrate it outdoors in an extended flight of the Stalker," he said.