Halo Alpha
Halo Alpha

“They have opened a path to the stars for all of us.”
— Tobias Fleming Shaw, ScD, QeD, FRS January 30, 2220 - November 10, 2317, Wallace Fujikawa ScD, QEnD April 20, 2215 - February 18, 2318[1]

The FTL drive from UNSC Spirit of Fire loaded aboard a transporter.

The Shaw-Fujikawa Translight Engine (SFTE) or human slipspace drive is a human spacecraft propulsion system capable of making transitions to and from slipstream space, thus enabling faster-than-light interstellar human travel.


Shaw-Fujikawa Noble Prize

Wallace Fujikawa and Tobias Fleming Shaw with their Nobel Prize for the discovery of Slipspace travel.

The engine was developed by a group of engineers and theoretical physicists led by Tobias Fleming Shaw and Wallace Fujikawa and was completed in April 2291.[1] From that point onward, the drive became one of the most important technological innovations of humanity.[2] The drive is not without limitations, although these may be partially because of slipstream physics rather than engineering imperfections.

By 2552, a vast majority of large human spacecraft were equipped with a slipspace engine, including most, if not all of the UNSC Navy's warships.

In 2553, the Tart-cart, a specialized Pelican dropship, was modified to use a slipspace drive. This is the smallest known human military spacecraft ever to use a Shaw-Fujikawa Translight Engine along with the Bogof, another modified Pelican.


HaloReach - Uppercut Slipspace Drive

A Slipspace drive being outfitted in orbit above Reach.

The Shaw-Fujikawa Translight Engine functions by creating ruptures, referred to in some sources as wormholes, between normal space and an alternate plane known as slipspace (also known as slipstream space and Shaw-Fujikawa space[3]). The nonstandard physics of slipspace allow it to be used as a shortcut realm, Facilitating Interstellar travel between distant regions in reasonable time.

The engine makes ruptures by using high-power cyclic particle accelerators to generate microscopic black holes. Because of their low mass, Hawking radiation gives them a lifetime of around a nanosecond (or potentially a little longer than a whole second)[4] before they evaporate into useless thermal energy. In that nanosecond, the engine manipulates them into forming a coherent rupture between normal space and the slipstream.[5]

An engine remains active for the entire period that a spacecraft is in the slipstream. When active, a Shaw-Fujikawa engine emits alpha (helium nuclei) and beta (fast electrons) particles.[6]

Human slipspace drives were considered black boxes[7] which were very difficult to repair or maintain after they went hot for the first time. Kurt-051 considered slipspace drives dangerous,[5] noting the aforementioned radiation and that space and time was said to distort around an active device. Dr. Halsey also observed that in the past, several technicians had simply vanished while manually adjusting a drive.[6] A ruptured slipspace drive can create slipspace "splinters" in normal space, eventually consuming the drive and the entire ship which the drive was placed on.[8] Mechanical failures like Slip Termination, Preventable, or STP, can also occur with Slipspace drives, usually resulting from poor maintenance.[9] Given their advanced technology, it is unknown whether the Covenant had a similar view.

The elements Selenium and Technetium are used to manufacture Shaw-Fujikawa Translight Engines.

Atypical uses[]

There have been several occasions where a Shaw-Fujikawa Translight Engine has been used for purposes other than those intended.

  • In 2531, UNSC Spirit of Fire reused its slipspace engine as an improvised bomb in order to induce a supernova in the miniature star at the heart of a Shield World, Shield 0459. The bomb worked perfectly, destroying the Shield World's interior after Spirit of Fire escaped.[10][11]
  • In the same year, the Office of Naval Intelligence used a partially deconstructed drive to cause Kurt-051’s armor to malfunction and send him flying into space.[5]
  • The UNSC has twice attempted to execute under-powered slipspace transitions. They were both unsuccessful and lead to the conversion of the trial spacecraft into “atomized bits.”[12]
  • Remembering an accident involving an improperly-mounted slipspace drive, Noble Team came up with a plan to use the drive of UNSC Savannah as an improvised weapon to destroy the CSO-class supercarrier Long Night of Solace. When the slipspace drive was activated, a massive slipspace rupture was created, causing the midsection of Long Night of Solace to be "teleported into oblivion."[13]

Covenant Advantages[]

Being more scientifically and 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 them to execute far more accurate slips.[12]

Covenant drives are currently more flexible and powerful than those of humans. They have thrice been seen to execute in-atmosphere slipspace transitions[14][15] (although the first time the drive in question was controlled by a human AI). Although two human ships utilizing the Shaw-Fujikawa engine are suspected of having successfully executed an in-atmosphere slipspace transition, this has not been irrefutably confirmed.[16]

Covenant drives can execute successful slips even if underpowered.

Another massive advantage of Covenant drives is that they travel significantly faster in slipspace than their human counterparts. Although exact velocities are difficult to measure accurately, human drives typically cover between 2-3 light-years per twenty-four hours while Covenant ships have been known to travel more than 900 light-years in the same time. Forerunner Dreadnoughts have been calculated at over 2,000 light-years per twenty-four hours.[17]

Although this advantage disappeared in the Post-War Era with ships like UNSC Infinity and its Forerunner enhanced drive.


The term for making a transition between normal space and the slipstream is "jump." The term "slip" is also used. Halo Wars refers to it as an FTL ("faster-than-light") drive and FTL reactor several times and the process of initializing it for a slip was referred to as "spinning up." The term "FTL drive" is also used in the story The Impossible Life and the Possible Death of Preston J. Cole in Halo: Evolutions.


  • The slipspace drive seen in Halo: Reach is much smaller than the one seen in Halo Wars.
  • Slipspace drives appear to emit an electro-magnetic pulse wave when activated, as seen during Operation: UPPERCUT when UNSC Savannah's drive activated on the Covenant corvette. A blue wave with arcing electricity expanded outwards, frying a nearby communications satellite.
  • Although the Covenant have a major advantage in terms of speed, the UNSC have the advantage of being able to use Slipspace drives in unorthodox methods. The Covenant only follow the protocols that are sanctioned by their religion and are unable or unwilling to stray from those protocols.
  • The elements that Shaw-Fujikawa drives use, Selenium and Technetium, are elements 34 and 43 respectively. Both of these make 7 if you add the digits. The sum of 34 and 43 is 77. Putting the numbers together and overlapping the 4 makes 343, which is 73.



  1. 1.0 1.1 Halo 3, multiplayer level Orbital
  2. Halo: Contact Harvest, page 24
  3. Halo: The Fall of Reach, page 141
  4. http://www.foxnews.com/story/0,2933,483477,00.html?=done
  5. 5.0 5.1 5.2 Halo: Ghosts of Onyx, page 53
  6. 6.0 6.1 Halo: Ghost of Onyx, pages 145-146
  7. “They had to repair the [drive] on the Magellan. It was a risky op. Those things aren’t meant to be taken apart once they go active.”, Halo: Ghost of Onyx, page 53
  8. Halo: Evolutions - Essential Tales of the Halo Universe - The Mona Lisa, page ??
  9. Halo: Contact Harvest, page 24
  10. Halo Wars, level Reactor
  11. Halo Wars, level Escape
  12. 12.0 12.1 Halo: Ghosts of Onyx, page 225
  13. Halo: Reach level Long Night of Solace
  14. Halo: First Strike
  15. Halo 2, level Delta Halo
  16. Halo: Evolutions - Essential Tales of the Halo Universe - The Impossible Life and the Possible Death of Preston J. Cole, pages 474, 484-485
  17. Sliptream Space

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