After being damaged by the Notum Cannons, an alien ship was forced to crash land in Andromeda. From this ship, alien larvae keeps pouring out. You're commissioned to enter the alien ship and kill the origin, the cocoon, that spawns these larvae.
The crash site is just to the north of ICC
The crashed alien ship lies in a narrow valley. Alien larvae crawl out of it and try to make their escape but brave low level volunteers prevent this.
Your job is to enter the ship, find the cocoon, and kill it.
The crashed alien ship
The logical way to find the main cocoon is to follow the stream of alien larvae that spawns from it. On your way you'll also encounter some more powerful aliens. So take your time and practice your pull skills until you reach the large cocoon room.
The main cocoon (after it was killed by my Santa MP) :)
The mission updates as soon as you've killed the cocoon.