There are the two Ram Tah missions which make you explore Guardian Ruins and Structures to decipher them and to learn about their lore. It takes a lot of time and travel, but it was certainly one of the most fun expeditions I've ever done in Elite. It's just a damn shame the logs you discover are not saved in the Codex (why? just WHY???).
Adding a number of similar hand-crafted "quest lines" would really add to the longevity of Elite. Especially now, when you can actually meet a fully voiced NPC "in person". Think of Quest lines that go deep into the lore and introduce players to the various factions, interest groups or actors and their respective agendas and politics.
Lori Jameson taking you through the Jameson Crash Site and that whole story.
Ram Tah mission getting some "cutscenes" in the form of voice acting and video comms.
I know people might feel like adding quests and story might make the game feel more gamey, but you know what... It is a game. And Galnet and Codex suck as a primary medium for "story".