Timeship
Timeships were vessels which had undergone temporal transit. Some timeships were designed and constructed for that purpose, while others underwent time travel through accidental or external forces.

The Federation experimented with sending vessels back in time as early as  2268, when the , under Captain James T. Kirk, used the light-speed breakaway factor to travel through time to visit mid-20th century Earth. () Seventeen years later, the same means was used to once again visit late-20th century Earth. ()

During the 24th century, use of a timeship or time travel was banned by the Temporal Prime Directive and care must be taken to avoid disrupting the timeline due to the risk of creating a temporal paradox. ()

During the 26th century dedicated timeships were in use, including those identified as time-pods. ()

By the 29th century the Federation maintained dedicated timeships in Starfleet, including  and Model HB-88 vessels. These timeships used both temporal rifts and a temporal displacement drive to travel through time. However, these ships required a great deal of experience to control, with inexperienced pilots running the risk of creating temporal explosions if any of their calibrations were off. () 

The practice of using timeships lasted into the 31st century, when an  from that century was discovered in the 22nd century by . () After a temporal war in that century, all time travel technology was banned and destroyed. ()

List of timeships

Officially designated timeships
These timeships were either operated exclusively to travel through time, or were sent on time-travel missions in addition to their primary goals.

"Unsanctioned timeships"
These starships and vessels were primarily intended for uses other than time travel, however through accidental or unofficial action they traveled to different eras.

See also 
 Lazarus' spaceship, also described as a "timeship"
 Daedalus Project

Appendices

Apocrypha
In the Department of Temporal Investigations novel Forgotten History, it is revealed that the newly-formed Department of Temporal Investigations attempted to create their own timeship in 2270 and again 2273.

The first attempt used the original engines of the USS Enterprise, then thought to be the only engines capable of performing a slingshot maneuver (due to their cold-start in ), basically adapting a stripped-down version of a Constitution-class engine system without a saucer section. However, their first attempt to create a timeship resulted in the ship being badly damaged after it overshot its target date and returned to the past at a point before its original departure. Its crew were able to avert the accident by aborting the planned flight, but this simultaneously confirmed that time travel could genuinely change history rather than simply creating a new timeline, as the future ship ceased to exist once the time of the originally-scheduled test-flight passed without the younger ship launching.

The second attempt combined the Enterprises original engines with a dimension-shifting capsule taken from the Vedala, with the goal of witnessing the future of parallel universes without the risk of changing history in their home universe, but the incompatible nature of the two technologies resulted in the ship becoming trapped between 2273 and 2383 in two different universes. As a result, the canon 2383 was nearly erased as other parties send advanced knowledge to their counterparts in 2273, until Lucsly and Kirk were able to bring the ship back into sync with its true timeline, Lucsly simultaneously teaching Kirk how to make any ship capable of performing a slingshot maneuver in future.

External link

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fr:Vaisseau temporel
ja:時間艦
Spacecraft classifications
Time travel technology