Project SPHINX was a UNSC Navy program created to install Covenant technology onto existing warships. Authorized in 2543, SPHINX's advances were slow but steady, as their early efforts were focused on developing interlinks and couplings needed to allow alien components to run on UNSC fuel systems and computer networks. Although well-funded, their project leads struggled to acquire the resources they needed for their experiments. Most of the ships they worked on were old, retired vessels that were too worn out or damaged to be used in the UNSC Navy, while they competed with ONI Section Three departments for the necessary artifacts they required.

Working from their base on the moon of Phocis the Groombridge 34 system, SPHINX's first major success occurred in 2548, when they successfully refitted a Phoenix-class colony ship with a hyperscanner array. After they installed a Covenant borer onto a UNSC ship in 2553, SPHINX became responsible for refitting UNSC command ships with captured technology.

Commander Kirk Butler, ex-Spartan-II washout, worked on the project. After the capture of several Huragok on the UNSC Gettysburg, two of these were assigned to aid in the project's integration and reverse-engineering efforts.