2511

January

 * January 3: All data pertaining to the planet Onyx is deemed classified.

February

 * February 15: Dr. Catherine Halsey delineates the fundamentals of the SPARTAN-II program, specifically her refinements in relation to the ORION Project.
 * February 23: Dr. Halsey learns of a terrorist with the Freedom and Liberation Party that detonated a commercial nuclear explosive in the Haven arcology, and proceeds to log this in her journal.

March

 * March 5: Jorge-052 is born in Pálháza on Reach.
 * March 7: John-117 is born in Elysium City on Eridanus II.
 * March 19: Linda-058 is born on Verent.

April

 * April 3: Frederic-104 is born on Ballast.
 * April 21: Douglas-042 is born on Asphodel.

May

 * May 4: Petra Janecek is born in Serif on Lenapi.
 * May 8: Jerome-092 is born on Minister.
 * May 16: Caleb-095 is born in Newport on Luyten.

July

 * July 10: Samuel-034 is born on Harvest.
 * July 17: Alice-130 is born on Passage.
 * July 30: Dr. Catherine Halsey outlines the basis of the piezoelectric mechanical enhancement of what would become the MJOLNIR Powered Assault Armor.

August

 * August 21: A terrorist associated with the Freedom and Liberation Party detonates a nuclear weapon at the Haven arcology on Mamore. The attack kills two million people and injures 8.3 million others.

September

 * September 8: Dr. Halsey writes down her thoughts regarding the recent breakthroughs on human neural cloning in relation to the flash cloning of the SPARTAN-II candidates. She informs Vice Admiral Michael Stanforth that the project will proceed to the candidate procurement stage.
 * September 15: Naomi-010 is born on Sansar.
 * September 21: Kelly-087 is born on Imber.

October

 * October 19: Kurt-051 is born in Mira on Circumstance.
 * October 22: A report is made on Forerunner artifacts that are found during routine excavations in an area designated Zone 67.

Unknown

 * Most of the future SPARTAN-IIs are born in this year.
 * Randall-037 is born in Hull, England, on Earth.