From Halopedia, the Halo wiki
UNSC Transit Dock L22 is an United Nations Space Command transit dock on Luna.
At some point following the Human-Covenant War, as part of Project ALOHA-19 an Artificial intelligence Armored matrix containment and display module was shipped from Havenwinter with S. J. Campbell signing for it on a June 14, to UNSC Transit Dock L22, Luna. It arrived on June 27 with a M. I. Castro signing for it. The module was then sent to Orlando on Earth to be used by Gabriela for an Outpost Discovery.