During the construction of the Majestic Seven, the Polaris' engines exploded, killing the construction crew. After the Coalition cleaned up the tragedy, the ship was repurposed into an orbital garden array, where plant life could be created and experimented to survive harsh environments for the purposes of seeding other colonies. The Gardens are a constant battleground between the XXIII Legion, rogue Winterkin, and minor Flesh infestations. Strange transmissions are also broadcast towards Mercury from some sectors.
Sol Orbital Gardens