From Halopedia, the Halo wiki
Began service:
Before December 30, 2552
Affiliation:
United Nations Space Command
Functionality:
AI computation network member
Phoenix is a UNSC artificial intelligence. On December 30, 2552, Codename: SURGEON and the AI Lackluster worked with Phoenix regarding the former's speculation that Vice Admiral Preston Cole remained alive and well after the Battle of Psi Serpentis. Together they established an 89.7% chance of Cole's survival.[1]