Warp five engine
The warp five engine was a type of warp reactor developed by Humans in the 22nd century in the Warp Five program and the NX Project. The  starships of the mid-22nd century were the first Earth ships to utilize the reactor. Warp five technology allowed Humans to travel a hundred times faster than had been possible with the previous generation of warp engines that were limited by the warp 2 barrier. ()

Specifications 

The engine was officially called a gravimetric field displacement manifold. () The reactor had eight major components. () Magnetic constrictors were used to align the positron stream to the dilithium matrix. () The dilithium matrix had to be aligned to within 0.3 microns. In the warp matrix, antimatter flow regulators controlled the plasma pressure in the intermix chamber. () Another important component of the reactor was the primary warp coil. ()

When the reactor was restarted from an off-line state, the reactor output had to be confined to within 300 and 312 millicochranes to prevent fusion of the dilithium matrix, unless the spatial compression index was greater than 5.62 percent, or the ship was within two parsecs of a class C gravimetric field distortion. ()

If the antimatter flow regulators were locked open, plasma pressure within the chamber would rise, threatening to destroy the ship. In order to reduce the pressure, the ship had to maintain high warp until the damage was repaired. Such an event occurred in November 2154, due to Klingon sabotage of . Moments before the engine was shut down and cold started, intermix pressure had risen to 1527 and the field variance had risen to eighty-seven millicochranes. ()

Even when the warp five engine was newly introduced and the only one in Starfleet was being used by Enterprise NX-01, warp five engines were expected to be installed in the next generation of freighters. ()

In the original configuration, warp factor five was the maximum speed that could be maintained by a ship using the warp five engine for fifty-three minutes only. This speed was first tested in 2152. () By 2153, warp five had become a sustainable cruising velocity that could be maintained for long periods of time. The speed of warp five corresponded roughly to a velocity of 200 times the speed of light. ()

In the mirror universe, the warp five engine was used by the Terran Empire, though it was known to leak delta rays. The radiation caused severe disfigurement to the engineers who worked on them. It was said that, for every year an engineer spent next to one, he lost a decade of his life expectancy. ()

Upgrades 
The plasma injector assembly of the reactor was upgraded in 2154, to allow a ship to maintain the speed of warp 5.06. () After the upgrade, the speed of warp 5.2 could also be reached for short periods of time. ()

The injector assembly could also be easily modified, based on Haradin schematics, to allow a ship to reach the speed of warp 6.9 for short intervals using the warp five engine. The structural integrity also needed to be reinforced on the NX-class ships for this to be possible. It was, however, determined that, using the Haradin modification, the injectors might overload at speeds over warp factor 5.6. Due to the risk, these speeds were not used by Enterprise. ()

24th century 

While the technology to go beyond warp five was achieved by Humans with the upgrades in the mid-2150s and by other future Federation member races such as the Vulcans much earlier, () over two centuries later, some smaller Federation starships, such as  runabouts still utilized a warp engine design with the maximum speed of only warp factor five (albeit by the updated warp scale). (, et al.)

bg:Двигател за пета светлинна
de:Warp-5-Antrieb
fr:Moteur à distorsion cinq
Warp