Endless Summer

Endless Summer (AI Serial Number 4279) was a "smart" AI attached to the UNSC excavation team on planet Onyx, Zone 67. He was sent to replace the AI Deep Winter after it reached the end of its operational life span in 2552. He took the form of a tall, red Cherokee Indian chief, bare-chested, wearing buckskins, and with a feathered spear in hand.

Unlike Deep Winter, and Eternal Spring before him, Endless Summer was aloof and did not care for Camp Currahee to the south of him. He barely tolerated the staff there, namely Spartan-051 and his Spartan-IIIs. Endless Summer never initiated communication with them unless in times of dire need.

Less than a year into his life, he was confronted with the attack on Zone 67 and Camp Currahee by the Sentinels of the planet. Endless Summer ordered the Spartan-IIIs to defend Zone 67 after the defenders of the area were all killed by the Sentinels. He was contacted by Dr. Catherine Halsey once she arrived, who convinced him to use the planet's Slipspace COM Launcher to alert Earth so they could send forces to save them. The Sentinels then found and destroyed the launcher.

Endless Summer is presumed to have been destroyed when Onyx exploded at the end of The Battle of Onyx.