The Spartan II program saw usage of flash clones, temporary replacements for the kidnapped children to keep suspicion at a low (with varying success). Do you think the chances are high that Halo’s greatest Human mind, Dr. Catherine Halsey has plans in place that if she were ever faced with mortality that she would clone herself? She has done a similar thing with the Smart AI that she created, but what about full body cloning? A perfect copy, maybe even with all her memories.
And do you think this same strategy would be used on certain high-value assets within ONI and the UNSC?
The flash-cloning technology can replace limbs or individual organs, but attempting to create a whole body produces one that will die within a few months or years. And while the clone can be given the memories of the original, it is still not the same person, and will develop different preferences. I recall this happening with the clones of the Spartan II recruits.
Halsey’s brain was cloned, and filled with her memories to create AI like Cortana and the Weapon, a process that destroys the brain. But the AI are not the same person as the person from whom the brain came from either.
Currently, the only way for Dr Halsey to gain immortality in the Halo canon would be if she acquired and donned a working set of Forerunner Armor which would analyze her DNA and reverse all of the damage to her body, revitalizing her, and rendering her biologically immortal for as long as she wore the armor.