Zephyr S, the solar-powered drone built by Airbus, has set a new flight-endurance record of nearly 26 days. Flying at an altitude of 21 km by day, the drone recharges batteries using solar panels, and uses two electric motors to stay aloft. At night the drone relies on battery power and also makes a slow descent to about 17 km.

Solar-powered drones may someday do at least some of the work of satellites, providing platforms for earth imaging, telecommunications, and scientific research. Drones cost only a fraction of the cost of satellites.

Airbus has built a launch facility in Western Australia which it plans to use for worldwide deployment of its aircraft, but the company says it can also establish regional launch facilities if necessary. Zephyr drones can traverse between one and two thousand kilometers per day.

Airbus is one of several companies pursuing solar drones — although that list does not now include Facebook, which dropped out of the race. Airbus soon will launch a larger version Zephyr T, used for bigger payloads.