Sentry gun

A sentry gun is a gun that is automatically aimed and fired at targets that are detected by sensors. The earliest functioning military sentry guns were the Close-in weapon systems point-defence weapons for detecting and destroying short range incoming missiles and enemy aircraft first used exclusively on naval assets, and now also as land-based defences.

Fictional sentry guns have appeared in science fiction since the 1940s. Video games have provided a fertile ground for fictional visions of sentry guns. Fictional examples of automatic sentry guns have appeared since the 1980s, in films such as Aliens (1986) and the television series Æon Flux (early 1990s).

Military use

Phalanx CIWS is an automated turret for missile defence

Samsung SGR-A1

The Samsung SGR-A1 is a South Korean military robot sentry designed to replace human counterparts in the demilitarized zone at the South and North Korea border. It is a stationary system made by Samsung defense subsidiary Samsung Techwin.

Super aEgis II

In December 2010, the South Korean firm DoDAAM unveiled the Super aEgis II, an automated turret-based weapon platform that uses thermal imaging to lock onto human-sized targets up to 3 km away. It is able to function during nighttime and regardless of weather conditions.

In fiction

Literature

• A sentry gun is used to pin down a group of rebelling colonists in Robert A. Heinlein's 1949 novel Red Planet. Michael Crichton's version, in the 1969 novel The Andromeda Strain, fired tranquillizer darts at intruders in the underground facility. Later, in 1980, Crichton wrote about a more advanced vision of sentry guns in his book Congo.

Video games

Video games have provided a fertile ground for visions of sentry guns. Although sentry guns first appeared in the Command & Conquer series , the Team Fortress mod for QuakeWorld solidified the sentry gun's position in gamers' vocabularies. Another early game that featured the sentry gun was Goldeneye 64. Various games, including Duke Nukem, Metal Gear, and Worms 4: Mayhem had several versions.

Many near-future and mid-future games make heavy use of sentry guns, often to fulfill level designer objectives: in the Modern Warfare series, they were used to slow the player's advance at key points and build tension, while in many other games sentry guns, often unseen, are used to constrain the player within a map area. Sometimes these become objectives in and of themselves, such as disabling their power supplies to allow the player to proceed, while in other cases they are permanent and serve to prevent the player from exiting the game world or map.

Film and television

Fictional examples of automatic sentry guns also appeared in the Special Edition version of Aliens. In the film, marines who were surrounded by Xenomorphs barricaded themselves into a sick bay facility, and deployed sentry guns to block access points to the sick bay. The weapons successfully repelled the alien adversaries until they ran out of ammunition. All references to this sequence were deleted from the theatrical print of the film, though Alan Dean Foster's 1986 novelization of the movie contained this scene. The sentry gun sequence was reinstated for the extended Special Edition cut of the film, released initially on Laserdisc in 1991 and much later on DVD.

As mentioned above, the film adaptation of Congo depicted a fictional laser-sighted remote sentry unit, which was used to repel the enemies. The science fiction television series Æon Flux depicted accurate sentry guns in multiple episodes. In the show, these guns, along with concrete walls, are depicted as a series of Fortifications separating two nations.

See also

• Close-in weapon system
• Remote weapon system

Specific systems:

• Phalanx CIWS
• Goalkeeper CIWS
• PROWLER