![marine_stalker](https://defense-update.com/wp-content/uploads/2011/08/marine_stalker.jpg)
Lockheed Martin has developed a ruggedized, fuel-cell powered version of its Stalker Unmanned Air System (UAS), called the Stalker eXtreme Endurance (XE) UAS. The new version quadruples the original Stalker’s flight endurance to eight-plus hours, without impacting the mobility of the unmanned system or the flexibility of its payload capabilities.
![stalker](https://defenseindex.com/wp-content/uploads/2011/08/stalker.jpg)
The complete Stalker XE system includes two aircraft, fuel cells, command and control ground station, support equipment, and small propane fuel storage tank. The standard air vehicle sensor is a modular dual daylight and night-time imager that allows persistent surveillance during the visual/thermal transition from day to night.
![marine_stalker](https://defenseindex.com/wp-content/uploads/2011/08/marine_stalker.jpg)
The Stalker XE system is powered by Ultra Electronics’ pioneering hybrid energy source using a propane fuel cell with a small, conventional lithium polymer battery to handle power peaks. This long-endurance fuel cell technology was developed through an innovative Defense Advanced Research Projects Agency (DARPA) sponsored effort led by Lockheed Martin and Adaptive Materials Incorporated (now a division of Ultra Electronics Holdings, plc). The DARPA project culminated with a rigorous flight test program including numerous back-to-back, long endurance intelligence, surveillance and reconnaissance high altitude and high wind flights proving that the Stalker UAS met or exceeded all technical and performance milestones.
“Missions requiring real time eyes-on a situation for extended periods of time, like border patrol, pipeline surveillance and special operations can now be conducted by a small UAS versus a larger, more costly system,” explained Tom Koonce, Lockheed Martin’s Stalker program manager. ‘The convenience and lower cost of a small UAS combined with extended endurance is a true game-changer.”