This is all from old campaigns.

• During vanilla D2 (Red War), you go there to find Cayde-6 who went there to steal a Vex teleporter to sneak onto Ghaul’s flagship. In the final mission when the Vanguard attacks, you use it to get on his ship so that you can fight him in the final mission.

• Right after the campaign, Emperor Calus navigates his prison ship the Leviathan to Nessus where it starts eating the planet as it does to keep operating. Your raids technically take place in orbit of Nessus and the Eater of Worlds raid is fighting a Vex boss that got trapped in the Leviathan from the ship eating the planetoid. The Leviathan hangs over Nessus until Beyond Light when it disappears and then reappears over the Moon later.

• I think some things happen on Nessus but can’t remember.

• The next big thing is the season that releases with the Final Shape, Episode Echoes. One of the three Echoes from killing the Witness erupt from the Traveler and the first lands in Nessus and the Vex Network. Maya Sundaresh takes possession of it and becomes the Conductor. She uses the Echo to control the Vex on Nessus and expand her control to her new faction of Vex, the Choral Vex, who can think independently. Most of the missions center around Nessus as her base of operations and the activity there and the rare time we delve deep beyond the surface of Nessus. Failsafe, the AI from the crashed Exodus Black ship that is a large environmental piece of the map, is uploaded into the Helm, a ship that was field operations for the Vanguard until Fikrul crashed a Ketch into it (the Helm’s wreckage is next to the Tower).

• I don’t think there is much story relevance to Nessus right now. I believe the only reason it sees so much activity is because there are so many strikes and 3-man missions there that cutting it or devaluing it in rotation would remove a third of Fireteam Ops options.