MJOLNIR

It was designed by Dr. Catherine Halsey a civilian scientist in the employment of the UNSC Office of Naval Intelligence section three. The armor has undergone several incarnations during the many years of its development. The armor line is named for the mythical weapon Mjölnir, the hammer of Thor, weapon of the Norse god of lightning, thunder, wind, and rain. The origin for the word "Mjölnir" is unknown. The Icelandic verbs mölva (to crush) and mala (to grind) have been suggested as possible translations. Another theory suggests that Mjolnir might be related to the Russian word молния (molniya) and the Welsh word melt (both words being translated as "lightning"). This second theory parallels with the idea that Thor, being a god of thunder, therefore might have used lightning as his weapon.
Dr. Halsey's decision to name what most would consider a defensive item after an offensive weapon tells much about her design philosophy for the project, namely that the Spartan-IIs designed to wear the armor would be primarily an offensive force.