"Offline, segment required", where do I get those segments?

I haven't played Warframe for a long time. Lots of changes have been made as expected in the user interface.

Now I am in my own ship (Liset) with many components/options disabled (I can access to my Arsenal after playing one game, but for example I still can't access my mods section). They all say "offline segment required" or something similar.

The game doesn't show me any kind of quest or guidance to find all the segments for my ship, yet the Warframe wikia says:

The Mods segment located to the starboard side of the ship by the lower deck allows a player to see any mods they have collected. They can also sell, transmute, and fuse mods in this segment. Activating the Mods segment also unlocks the ability to upgrade and customize a player's Warframe and weapons' mod loadout on the Arsenal segment. The Mods segment can be picked up by rescuing Darvo on Mariana, Earth.

But the sector of the planet doesn't pop-up as a rescue mission: it's a sabotage mission. I've played it and everything but nothing changed. What should I do?