Slipstream Drives are devices that allow a starship to travel through an extra-dimensional plane known as Slipspace and in some places called Dark Space or Hyperspace. This extra-dimensional plane is a parallel overlapping universe where Dark Matter, Dark Energy, and Tachyons are naturally found. This area of space allows for travel faster than the speed of light without time dilation or injury to the crew from relativistic thrust. Simply put, it is a place where the laws of newtonian physics no longer apply.
Entering Slipspace can only be done at certain specific points. These Slipknots are found 5 Astronomical Units (41.58 Light Minutes, 747.98 Gigametres) above and below the corona of a star. These Slipknots must be entered at speed from specific angles. Any standard nav computer can calculate a path for entry. Especially powerful Slipstream Drives can enter from a greater distance and the larger the ship, the more powerful a Slipstream drive must be.
Slipstream drives work by manipulating the powerful electromagnetic field projected in front of a starship to prevent collision with hypervelocity micrometeoroids. By running the current from this field through an Exotic Matter Lense it produces manmade Dark Energy. At these Slipknots, or Transit Points, Dark Energy is pulled into Slipspace. This is known as "to Slip" or "to Transit". The process has a visual component as Dark Energy seeps from the Slipknot and a ripple in space when the ship is pulled in. When this occurs it is very dangerous for anything caught in the area unless it too has a Dark Energy signature.
Once inside Slipspace the transiting ship is propelled by its sail of Dark Energy through the Slipspace Streams. These streams are areas of dense Dark Energy that is pushed and pulled by stellar masses through tight gaps in massive Dark Matter formations. Ships cannot collide in these streams, as they possess no mass in Slipspace. Instead passing through one another, none the wiser. This also has the fortunate effect of preventing simultaneous exit from Slipspace. When modulating the Dark Energy field to trigger expulsion from the Dark Energy stream only one dense collection of particles, such as matter, can pass through the Slipknot's energy vortex at a time. To other ships it simply appears as if they arrived from the opposite exit.
While travelling through Slipspace a ship cannot be detected save for a rise in background radiation that occurs within 1 AU (8.3 Lightminutes, 149.6 Megametres) of a Slipknot. While within Slipspace a ship cannot send or receive signals of any kind. It is impossible to sense anything other than the fluctuations of the Dark Energy, which signal an exit point. To a sophont's senses Slipspace appears as an unending field of iridescent white with silver at the edges of Dark Matter masses. It is so bright that no known sophont species can look on it unaided. Doing so would result in instantaneous retinal damage and permanent blindness. Unshielded exposure to Dark Energy is instantaneously fatal. The failure of one's Slipstream Drive while in Slipspace results in the immediate destruction of the starship.