Project JAVELIN
From Halopedia, the Halo wiki
Project JAVELIN is a UNSC project, likely managed by the Office of Naval Intelligence. Dr. Catherine Halsey noted JAVELIN as a potential parallel program to the SPARTAN-II Program. After witnessing members of NOBLE Team Halsey surmised that they might be products of JAVELIN, though they were actually SPARTAN III's. Given this context, it is possible that Project JAVELIN also involves biologically augmented supersoldiers or powered armor.[1]
