The Dimensional Fold Drive is an extension of existing Warp Drive technology. It was developed by melding Hyperspace technology produced and sold by Excalibur Inc. and Federation Warp Drive technology. It is used to travel not only through space, but also through time.
Operation
The drive works as an extension of Warp Drive by infusing the the warp field with a temporal energy (a specifically calibrated mix of tachyons, chronotons, and lygons) which create more drastic changes in the surrounding space-time. This alteration of space-time folds the space around the vessel back into itself in a controlled spacial implosion. Using the vessels warp nacelles in consort with the main deflector and static deflector grid to control the implosion and the space of the resulting bubble of space-time the vessel is able to create pocket. This pocket is tethered to real space-time but exists outside the normal space-time flow. This region (called null-space) exists in an infinite plane between real space and adjacent subspace domains.
Connection to Real Space-Time
The space-time anchor exists in real space as a verteron particle nexus which prevents the space-time bubble from separating from its native reality. This particle nexus moves through real space proportional the vessels path through null-space. Since the vessel itself is not moving relative to it's space-time pocket it experience no initia nor is the vessel impacted by the corresponding tether's position in real space. The pocket itself is affected by forced proportional to its distance in subspace from real space (i.e. the length of the tether). The vessel alters the direction of travel and velocity by altering the field geometry and how far into null-space the pocket is. A natural equalibrum of relational speed in real space to energy output and field geometry occurs making speed a constant relative to the shape of the pocket and relative position in null-space.
Neither matter nor energy can exist for more than seconds before being pushed back into normal space at random. A ship or person cannot survive intact the uncontrolled transition intact. A ship's debris would be spread over an entire sector or farther, if folded space collapsed around it.
Velocity
The velocity relative to a position in normal space-time is calculated based on transition between 10 levels of of flight through null-space in the folded space-time pocket. These levels are termed Fold Factor or sometimes Fold Depth, each level corresponds to a specific output and geometry based on the shape and size of the vessel to produce a specific velocity of position in real space. Where x is the fold level, the following function gives speed cochrans.
Roughly 1 cochran moving through a region with a space-time gradient of 1 (that is to say no distortions in the local space-time) is equivalent to the speed of light in a vacuum. Partial fold factors are also allowed, so it is possible to travel at a velocity between Fold 5 and Fold 6 and the relative speed in real space would fit the predicted speed by the above function.
Efficiency
For a Fold Factor of 2 or less, it is more efficient to use Warp Drive due to the power output for velocity gain over Warp Drive. Transitioning to Fold 3 and higher, there is a significant speed differential for a similar (though generally higher) power output for the same Warp Factor.
Communications / Sensing
Sending / communicating while moving through null-space is difficult at best. Usually some form of specialized beacon or receiver is required to do so. Currently Solas Tempus operates several transceivers which allow communications with vessels travelling in null-space. Due to the proprietary nature of the technology, only Solas Tempus has technology to reliably communicate with a vessel in null-space.
Time Travel
Velocity
Velocities are measured in chochranes like with Warp Drive as multiples of c (light speed) adjusted for variations caused by local space composition, gravity, and subspace geometry. While normal Warp Drive has a speed curve of roughly warp factor raised to the 3 and 1/3 power, Folding allows for a steeper speed curve of folding factor raised to the 3 and 2/3 power.
It may be possible to push the envelope further into the dimensional void to achieve greater speed, but it is likely not safe with current technological limitations.
Time Travel
When in Folded Space a vessel can alter its delta-T vector (direction and velocity of travel through time) but also may keep the delta-T set to 0, where the vessel will not travel through time except along its normal, natural, speed and direction. Altering the delta-T also uses considerably more power than simply traveling in the three spacial dimensions.
Terminology
Terminology used to differentiate between speed requests or in reporting speeds for course corrections or other records is warp 9 is Warp Drive. A similar speed with folded drive is termed as Fold 9, meaning traveling in folded space.