Fleetbase Korus, Phobos is a Grimoire card from the original Destiny (Destiny 1), found under Places → Mars. Grimoire cards held most of the game's lore and were read on Bungie.net and in the companion app, not in the game itself.
Card text
Discovered by Holborn’s Host in association with Lord Shaxx and a Redjack fireteam, Fleetbase Korus marks the largest known Cabal orbital defense station in-system. Reports have the Fleetbase under the command of a triumvirate headed by one Primus Ta’aun, and his fleet battalion commanders Valus Tlu’urn and Valus Mau'ual. The Skyburner fleet has yet to be deployed against the City, bringing Zavala the fear that the Cabal have yet to launch their core campaign.
Grimoire text written by Bungie, shown as it appears in the Destiny 1 game files.