The UNSC Spirit of Fire (CFV-88) was constructed in 2473 but was recommissioned and refitted 50 years after its construction for military purposes. After its recommissioning the ship was used to transport equipment and civilians to planets as part of the UNSC's expansion efforts. The Spirit of Fires on-board AI is known as Serina and the final civilian captain of the ship was Captain Alexander who retired on 20th July 2520 after the colonization of the planet Verent. In 2520 the Spirit of Fire was converted into a warship and a MAC cannon was installed along with a large array of other weaponry, the massive storage bays that were designed to hold large quantities of equipment and civilians now served as a highly effective means of storing military vehicles, construction supplies and repair equipment.
The Spirit of Fire was involved in the Harvest Campaign, the 5 year campaign to retake planet Harvest from the Covenant, where it provided UNSC troops with supplies, reinforcements, ground and aerial vehicles, orbital strikes, and more. By early 2531 when the final battle of Harvest ended the ship was captained by Captain James Cutter and two other major characters of Halo Wars, Professor Ellen Anders and Sergeant John Forge were also aboard ship. Immediately after the end of the Harvest Campaign the Spirit of Fire traveled to planet Arcadia where it assisted in the evacuation of the planets colonists and in the battle against the invading Covenant.
When Ellen Anders was kidnapped by Covenant Arbiter Ripa 'Moramee the Spirit of Fire pursued the Arbiter's flag ship into an unknown system and onto a Flood-infested planet. The planet was eventually discovered to be a Forerunner Shield World and in its time there the troops of the Spirit of Fire became locked in a simultaneous battle against the Covenant, Flood and the Shield Worlds defense systems, which the ship aided them in. At one point the ship itself even came under direct attack from the Flood who were attaching themselves to the hull in an attempt to infest the ship, however a combination of efforts by the on-board troops and the Shield World decontamination systems stopped the infestation. Shortly after arriving in the interior of the Shield World the Spirit of Fire also had the misfortune of colliding with a Covenant Destroyer and the ships power core had to be repaired by Cyclops units while the rest of the crew was fighting off boarding Covenant forces.
The Covenant had great interest in the powerful Forerunner warships contained within the Shield World and so to stop the Covenant coming into possession of such ships the Shaw-Fujikawa Translight Drive (a drive used for faster-than-light travel) of the ship was detonated inside the artificial sun of the Shield World, causing a massively destructive explosion within the Shield World which the Spirit of Fire managed to narrowly escape. The Spirit of Fire was left stranded in uncharted space without any means of faster-than-light travel, meaning that it would take years to decades to reach colonized space again. Most of the crew went into cryogenic sleep at this point, leaving only a skeleton crew to man the ship awake.
On 10th February 2534 the UNSC changed the status of the Spirit of Fire from "missing" to "lost with all hands" for a reason which remained top secret. A memorial service was held in the memory of those aboard the ship but many relations to those who were aboard the Spirit of Fire did not attend, continuing to hope that the missing were still alive.
- The motto of the Spirit of Fire, "Exita Actus Probat" is Latin for "The ends justify the means".
- In 2530 the ships thrust assemblies were replaced with those from the destroyer ship UNSC Calcutta, increasing their output by 37%.
- Before its involvement with the First Battle of Arcadia, the ship had visited the planet two other times. The first time to aid in the colonization of the planet and the second time to aid local authorities in handling a violent student riot.
- The Spirit of Fire is 2.5 kilometers in length.
- The vessel has 8 thruster units.
- The hull of the ship is made from Titanium-A.
- In a single day the Spirit of Fire can travel 2.625 lightyears through Slipspace.