The UNSC Infinity (INF-101) was a vessel commissioned into the UNSC Navy following the end of the Human-Covenant war in 2553. The Infinity was a starship technology demonstrator, using recovered technology found during the war against the Covenant Empire and from Forerunner facilities and installations. Infinity's on-board AI, Roland, oversees all activities on the ship.
The UNSC Infinity is seen in the Halo 4 demo from E3 2012 drifting near Requiem with a UNSC Frigate escort alongside. It is then attacked with what appears to be an EMP blast, and crash-lands on Requiem. On Requiem, the UNSC Infinity came under attack by Promethean ground forces.
Later on, the Infinity was able to take off and continue further operations on Requiem.
This starship was constructed in the Oort cloud on the outskirts of the Sol System. The Office of Naval Intelligence attempted to keep the ship's construction a secret by permanently stationing workers in the Oort cloud while maintaining a complete communications blackout.
This ship is to receive upgrades, particularly slipspace navigation which was reverse engineered from the Forerunner technology retrieved from Shield World Trevelyan as well as modified communications allowing ships to communicate even in slipspace. These modifications delayed the Infinity from full deployment as it was still not complete and with the modifications it would take even longer.
Andrew Del Rio was assigned as the captain of the Infinity. The rest of the crew consisted of several SPARTAN-IV personnel. They were assigned to her before the preliminary trials on the ship began. There are 17,000 of humanity's "brightest and best" on board.
The Infinity is approximately 5.6 kilometres (3.5 miles) from bow to stern, placing it as the largest UNSC vessel. Technical specifications are yet unknown, and based upon the given image of the Infinity, it seems to look incomplete since some of the sections appear to be exposed. The Infinity was given "Every scrap of Forerunner technology that the UNSC picked apart during the war." It has a primary armament consisting of 4 Magnetic Accelerator Cannons. Its hull and shielding have been shown to be immensely powerful, as demonstrated when it rammed a CCS-class battlecruiser and destroy it with next to no damage to itself.
The Infinity's primary armament is four CR-08, Series-8 Mass Accelerator Cannon. Infinity boasts a significant missile network that can be implemented for ship-to-ship combat, anti-air defense and orbital gunfire support for Marine forces. Placed throughout the ship are 1100 missile pods of three types: Archer, Rapier, and Howler, totaling the ship's missile payload at 25900 missiles. Close-in defense against enemy missiles, fighters, and boarding craft is provided by the ship's M965 Fortress point defense system, a network of 830 70mm automatic cannons. It also had a Mark 2488 Magnetic Accelerator Cannon on the top of the ship.
The original purpose of Infinity was to beat back the Covenant in the event that Earth was lost and humanity needed a last resort, however that was no longer applicable after the conclusion of the Human-Covenant war. After the war it was re-purposed as an expeditionary and exploratory ship. The Infinity participated in the rebellion during Sangheilios as ONI did not want the state of Vadam falling too quickly or to have the Arbiter winning too easily. It is also the location of a SPARTAN-IV training site. The Infinity's current mission is to locate the remaining Halo Rings and other Forerunner installations and establish bases on them to oversee their decomission. At Installation 03, the Infinity was tasked with the removal and relocation of the Composer to the nearby Ivanoff Research Station, a process which took over 3 months as said by Dr. Sandra Tillson.
- Marathon Infinity is a game created by Bungie, and the possible namesake of the ship.
- In Halo 4, this ship was sent to an unknown location with the SPARTAN-IVs aboard for training, this is the reason for the Red and Blue Spartans fighting each other in the multiplayer.
- At over 5 kilometers long, the UNSC Infinity is the largest ship in the fleet, rivaling a CAS-class assault carrier which is over 5 kilometers long from bow to stern.
- The Infinity also devotes one entire deck of the ship for the training of the SPARTAN-IVs.
- The final design for the Infinity was supplied by Ansel Hsiao, a 3D Artist who previously submitted artwork for the Star Wars guidebook The Essential Guide to Warfare.
- The shape of the new Railgun resembles that of the Infinity iteslf.
- The Infinity has been seen in the Spartan Ops trailer to ram into a Covenant CCS-class Battlecruiser head-on and suffer little to no damage while the other ship was torn in half.
- As Shown in the first spartan Ops cinematic, the Infinity is capable of launching a number of Charon-class light frigates from a launchbay on it's underside.
- At the end of Halo 4: Forward Unto Dawn the UNSC Infinity can be seen escorted by 13 Halcyon-class light cruisers, and 28 Paris-class heavy frigates right before entering Slipspace, making it a total of 41 ships escorting the UNSC Infinity.
- The Infinity is equipped with what appears to be two bow mounted Energy Projectors in place of the traditional MAC Cannon that it uses to punch a hole in Didact's ship.
- The Infinity appears to have a AI called Roland, he has so far only been seen in the episode "Departure" found in Halo Waypoint Spartan Ops. Roland's avatar is in the form of a World War 2 pilot.