From Halopedia, the Halo wiki
- February 7: The Stalwart-class light frigate UNSC In Amber Clad is formally commissioned into service, the last of sixteen such vessels built at Anchor 9.
- May 21: ONI Section Two publicly unveils the SPARTAN-II program in order to boost morale during the Human-Covenant War. Because each super soldier is said to have killed thousands of Covenant troops, many consider the Spartans to be the stuff of legend, unless having encountered one. The existence of the SPARTAN-III program remains confidential.
- September 4: The UNSC frigate Tripping Light is dry-docked for repairs. Dr. Catherine Halsey uses the ship's Slipspace drive in an experiment to build an AI housing fractal within Slipspace. While the test is eventually a failure, the Assembly takes note of this as an incredible scientific breakthrough and even discusses the possibility of permanently moving into such construct to escape in case humanity were to lose the war.
- The colony Skopje is attacked and subsequently glassed by Covenant forces.
- An ONI patrol drone records a violent meteor collision in an unspecified space site. A UNSC research facility is later established in this location to study the impact event.
- Kerstin Sentzke, Edvin Sentzke's daughter and Staffan Sentzke's granddaughter, is born.
- The secret Sabre Project is developed.
- Bungie.net: The Spartan Project
- Halo: Ghosts of Onyx, page 139
- Bungie.net: Halo 3: ODST Field Guide
- Dr. Halsey's personal journal, September 4, 2547
- Halo: Reach, Data pad 17
- Halo: Evolutions - Essential Tales of the Halo Universe, Dirt
- Halo 4, multiplayer map Impact description
- Halo: Mortal Dictata, page 105
- Halo: Fleet Battles, Core Rulebook - page 125