SPARTAN-III program
From Halopedia, the Halo wiki
Summary
The Spartan-IIIs were never really mentioned except when the Spartan-IIs graduated. That was the last anyone ever seen of Chief Petty Officer Mendez. Then when Dr. Halsey was snooping around in Colonel James Ackerson computer files, she found a file named S-III. It contained the complete medical files on all Spartan IIs, Along with extensive files on the flash clone process used to copy them. Then there was a file named CPOMZ that contained a star chart. Dr. Halsey belived this is where Ackerson has Chief Mendez training the Spartan IIIs. Then when Dr. Halsey sedated Spartan-087 and stole Governor Jacob Jiles's ship and escaped through Slipspace. Many fan-made scripts have included Spartan IIIs. Some people think Halo 3 will explain Dr. Halsey's secret mission.
Known Spartan IIIs
Spartan-458- Active
