Lockheed Martin Stalker

https://en.wikipedia.org/wiki/Lockheed_Martin_Stalker

The Stalker was a hand-launched, electrically powered unmanned aerial vehicle
developed by Lockheed Martin Skunk Works for an unspecified customer, presumably
United States Special Operations Command. It was used for military applications,
such as providing intelligence, surveillance, and target acquisition.

The Lockheed Martin Stalker was created in 2006 by the same Skunk Works team
responsible for the Desert Hawk. It was hand launched and belly landed, had a
quiet electric motor and propeller, and carried a detachable camera payload. The
camera system had modules for daylight, low light, and infrared. The camera
system could be removed and replaced with droppable payloads.

The Stalker used a self-sustaining propane-fueled tubular solid oxide fuel cell
(SOFC) system developed by the U.S. Army Research Laboratory (ARL). The 245 W
system was designed to cope with environmental and operational stress,
particularly with wide ranges of temperatures, weather, altitudes, vibrations,
and sudden impacts.

Research on SOFCs began at General Electric and Westinghouse in the early 1960s.
The later research on fuel cell technology within the United States Government
was focused through the Department of Energy and the Defense Advances Research
Projects Agency.

ARL focused specifically on SOFCs because they can run on hydrocarbons, such as
propane and butane, rather than the pure hydrogen other types of fuel cells
require. One constraint on the design was the ability of the system to survive
multiple thermal cycles. To meet this constraint, a tubular design was preferred
rather than a planar one.

A propane fuel cell powered version of the Stalker with 8 hours endurance
(quadruple the 2 hours available on battery power) was developed. The fuel cell
powered Stalker was in over 80 missions in Afghanistan. The Army was hoping to
create a fuel cell that runs on JP8 fuel rather than propane, as it was more
common in the logistics inventory.


Role
Unmanned Aerial Vehicle

National origin
United States of America

Manufacturer
Lockheed Martin Skunk Works

First flight
2006

Introduction
2006

Primary user
United States Special Operations Command

Specifications (Stalker)

General characteristics
Crew: none
Wingspan: 10 ft (3.0 m)
Empty weight: 14.5 lb (7 kg)
Max takeoff weight: 17.5 lb (8 kg)
Fuel capacity: 2+hours
Powerplant: 1 × Hush Drive Electric
Propellers: 2-bladed

Performance
Maximum speed: 50 mph (80 km/h, 43 kn) (dash)
Service ceiling: 15,000 ft (4,600 m)




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