Lockheed Martin’s Skunk Works advanced development programs division has achieved a new world flight endurance record for a Group 2 (5 to <25 kg (11 to <55 lb.)) drone after the company’s Stalker VXE remained aloft for 39 hours, 17 minutes, and seven seconds.
Endurance is a vital commodity for drones in both large jet-powered units and in a smaller, portable craft like the Stalker XVE.
Lockheed’s Stalker line of UAVs was first developed in 2006. Since then, it has gone through a series of upgrades over the years to improve its endurance and other capabilities. The latest iteration, the Stalker XVE, is portable and is packed away in two large plastic cases. It can be assembled by one person and needs only one operator because of its autonomous avionics.
The Stalker XVE is open architecture and configurable to suit mission requirements. It only weighs about 44 lb (20 kg) and it uses electric propulsion powered by either a propane-fueled Solid Oxide Fuel Cell (SOFC) providing an endurance of eight hours with a 5.5 lb. (2.5 kg) payload, or by a battery giving a flight time of about four hours.
The maximum speed is 58 mph (93 km/h) and it can reach a top height of 12,000 ft (3,658 m). The Stalker VXE can be launched by bungee, rail, or VTOL.
For February 18, 2022, flight at the Santa Margarita Ranch in California, the production Stalker XVE was configured for endurance using the SOFC and an additional propane fuel tank installed under the starboard wing.
The world record is not official yet but Lockheed has applied to the Fédération Aéronautique Internationale (FAI) through its US affiliate, the National Aeronautic Association, for certification. The hope is that the endurance flight, which is almost five times longer than the normal Stalker flight, will help in enhancing the capabilities of the drone.