https://www.gamespot.com/articles/destiny-2-servers-down-for-maintenance-update-now-/1100-6453743/

Destiny 2 players will have to find something else to occupy a few hours of their time today, October 3, as Bungie has taken Destiny 2's servers offline for scheduled maintenance. This will be followed by the release of a new hotfix update and the kickoff of Victory Week, which caps off the recent Faction Rallies event. [Update: Servers are now back online ahead of schedule; hotfix update 1.0.3.1 is live and a Faction Rallies winner has been announced. If you're having trouble signing in, Bungie recommends closing and re-opening the game.]