South Korea's EAV-4 solar drone completes a 170-hour flight in the stratosphere

The Korea AeroSpace Administration has disclosed that the EAV-4, a solar-powered stratospheric drone developed by the Korea Aerospace Research Institute, flew without stopping for 170 hours and 5 minutes, Drone Magazine reports. It took off near Goheung Bay in South Jeolla Province on 18 August, landed on 25 August and reached a top altitude of 21.2 km.

That is more than three times the 53 hours flown by the earlier EAV-3 in 2020, until now the longest continuous flight in South Korea. The EAV-4 has a 31 m wingspan and a maximum take-off weight of about 150 kg, can carry up to 20 kg of equipment, and stores solar power in batteries to fly at night.

During the test it also looked for wildfire ignition points from 14.4 km with electro-optical and infrared cameras and tracked how the smoke spread. The agency plans private-led follow-up development until 2030, with three demonstration aircraft for wildfire and sea monitoring, and aims eventually to extend flights to up to 100 days.

The agency rates the endurance result as the second best in the world, although comparisons depend on aircraft weight and mission; Airbus's Zephyr announced a 67-day continuous flight in 2025.