In the depths of outer space, a huge block of vessels tied them adrift in a vacuum. On board, the biggest threat in the history of mankind is being prepared. The Space Marines are responsible for cleaning the depths of Hulk abomination xenos ...
An ingame video of the mission "transfer the STC data". The goal is to protect the transmitter from Chaos troops until the files are send to Space Marines' ships.
I lose the game, I think it's because of the Chaos Terminators :D