The Emergency Security Hologram or ESH is a sophisticated holographic program used aboard Starfleet ships and facilities in the latter part of the 24th century.

Developed by Doctor Lewis Zimmerman and Reginald Barclay, the ESH was developed based on the success of the Emergency Medical Hologram programs. The first ship to use the ESH was the USS Galen, which also pioneered a number of other advanced holographic staff, including upgraded EMH staff and holographic engineers.

In 2381, the Galen was assigned to Project Full Circle and, shortly in to the expedition The Doctor and Lieutenant Barclay suggested that the ESH's should be tested. When Clarissa Glenn, the ship's commander, questioned the necessity of this, they explained that the matrices used in creating the ESH's had been based on some of the more feared species that the Federation had encountered, including the Klingons, the Hirogen and the Gorn, something which the non-holographic crew members would not be used to. Each of the designed species had also been developed to fight in the appropriate fashion. (VOY novel: Unworthy)

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