2491

2491 was a year in the 2490s in the 25th century.

January

 * January: 48452-556-EPN644, a member of the Assembly, submits himself for vivisection by the humans, with the intent of sparking an interest in the long-dormant Orion Project.
 * January 29: The Orion program is re-initiated.

April

 * April 2: The planet Onyx is discovered and first investigated in this year.

May

 * May 6: A report is made on Onyx, the planet being recommended for colonization.

July

 * July 8: Chieftain of the Jiralhanae Tartarus is born on Doisac.

Unknown

 * Elias Carver publishes a set of theories known as the Carver Findings.
 * The Assembly decides to have Onyx removed from the list of potential planets for colonization, due to the advanced alien technology present on the planet.
 * The M99 Stanchion presumably enters production for service within the UNSC.
 * The position of captain of the Spirit of Fire is transferred from Captain Rehkov to Captain Donald.

Circa 2491

 * Between October 25 2490 to October 23 2492: Rear Admiral Ned Rich is born.