Slipspace drive

A Slipspace drive is a device designed to make transitions in and out of an alternate plane known as slipstream space, allowing faster-than-light travel.

Overview
A slipspace drive functions by creating ruptures between normal space and slipspace. The nonstandard physics of slipspace allow it to be used as a shortcut realm, facilitating interstellar travel between distant regions in reasonable time.

A slipspace drive does not actually "accelerate" a spacecraft through slipstream space; this is performed by the ship's conventional reaction thrusters. Thus, ships with more powerful conventional engines are also faster within the slipstream. As astrogation, the coordination of slipspace jumps, cannot be successfully done by a human, the calculations involved in a jump are done by a navigation computer or an AI.

Human
Developed in 2291 by the physicists Tobias Fleming Shaw and Wallace Fujikawa, the Shaw-Fujikawa Translight Engine generates ruptures by using high-power cyclic particle accelerators to generate microscopic black holes.

Throughout much of the Human-Covenant War, the technology was still limited and jumps typically took from several weeks to months, with longer jumps taking over half a year. By the end of the war, human advances in science and engineering, as well as captured Forerunner technology allowed for the construction of slipspace drives almost on par with those of the Covenant. The was capable of making slipspace transitions within an accuracy of one kilometer, and within one second of expected arrival time.

Covenant
Being more technologically advanced than humanity, the Covenant have numerous advantages in slipspace propulsion systems. Whilst the Shaw-Fujikawa engine is said to “punch” a hole between realms using brute force, Covenant engines instead take a small rupture and delicately enlarge it with surgical precision. This allows the latter to execute far more accurate slips. Covenant slipspace drives are often referred to as "jump drives". In addition to their more powerful thruster engines, it has been theorized by the UNSC that Covenant drives generate several "microjumps" within a single slipspace transition to measure the dilation involved in a jump, allowing them to reach their destinations faster.

Covenant drives are generally more flexible and powerful than those of humans. They have thrice been seen to execute in-atmosphere slipspace transitions (although the first time the drive in question was controlled by a human AI). In addition, Covenant drives can execute successful slips even if underpowered.

Forerunner
Forerunner understanding of the mechanics of slipspace far exceeded that of the UNSC or the Covenant. They used small crystals embedded in their slipspace drives to manipulate slipspace, allowing smoother transitions. They had a superior grasp of reconciliation, the ability to automatically correct or otherwise manipulate the causal effects of slipspace travel. This was useful when carrying out large-scale coordinated military campaigns or simply moving across enormous distances.

Forerunner ships are also extremely fast, as seen when the Mantle's Approach was able to travel from the vicinity Installation 03 to Earth in a matter of minutes. Forerunner ships rely on their energy shields to keep them safe during the journey unlike UNSC ships which rely on just their armor.