Melissa
From Halopedia, the Halo wiki
Summary
Melissa was an artificial intelligence construct created by using Yasmine Zaman's brain. Yasmine had been in the Spartan-II training program, but washed out at fourteen. They used her brain to create Melissa, the AI of the UNSC stealth ship Apocalypso.
Melissa was infected by a program that the Covenant created to attach itself to the AI that recieved the transmission it was buried in. When the Ark created a Slipspace explosion on return to Earth, she was blown apart, one part being transmitted to Earth of the present, and the other was thrown back in time to the Earth of the early 21st century.
She was finally put back together after she helped disarm the Ark in Boston. She had just about gone rampant when the field that had seperated her two halves dissolved and she regained her sanity.
Though technically a rogue, she continued to help her friends reach safety before the Covenant attack, which was brought upon them by the Ark's Slipspace ripple that was initiated upon it's disarming.
Melissa had several nicknames. She was called "The Operator" by her crew on the Apocalypso and was called "Durga" by her friends on Earth in 2552 after she was blown apart. The part that was thrown back in time called itself The Queen and the Sleeping Princess. The Sleeping Princess was the part of Melissa that still retained memories of Yasmine's life.
Images
http://img86.imageshack.us/img86/6130/melissathumb7vd.jpg
