GTR-18 Smokey Sam

The GTR-18A, commonly known as the Smokey Sam, is a small unguided rocket developed by the Naval Weapons Center as a threat simulator for use during military exercises. Widely used in training, the Smokey Sam remains in operational service with the United States military.

Design and development
The GTR-18 was conceived in the late 1970s by Robert A. McLellan, a Weapons Range Scientist working with RED FLAG at Nellis AFB. He first searched for a commercially available system that would perform as he envisioned. It quickly became apparent that no commercial product would perform adequately, so the development of the GTR-18 was undertaken by the Naval Weapons Center (NWC) during the early 1980s, with the intent of developing Mr. McLellan's idea of a simple and inexpensive rocket for visually simulating the launch of surface-to-air missiles (SAMs) during training exercises.

Constructed from phenolic paper and styrofoam, the Smokey Sam is designed for minimal cost and, in the event of accidentally striking low-flying aircraft, to cause minimal damage.

Operational history
The complete launch system, known as the Smokey Sam Simulator, includes single- and four-rail launching pads, an AN/VPQ-1 radar set, and the GTR-18A rockets themselves, making up the SMU-124/E system as a whole.

When launched, the GTR-18's rocket motor produces a distinctive white plume, providing a realistic simulation of the launch of a surface-to-air missile. While the ordinary GTR-18A has a simple, model rocket type motor, an improved 'Dual Thrust Smokey Sam' tested in the early 2000s featured a modified rocket motor, providing a 1.5 second boost period, followed by a lower-thrust sustainer burn with burnout occurring at 7.1 seconds after launch.

Receiving the altered designation DGTR-18A in the early 1990s, the Smokey Sam remains in production and operational service, being extensively used by the U.S. military.