When you were placing the bomb on board the cruiser, some elite mercenaries captured you and put you in their base. the guard behind you closed 2 blast doors so there is no turning back. Up ahead is a rancor pit, its your only chance of escape. When you get into the pit, there will be a gun and armor from dead guys, use them to kill the rancor. Then follow the hallways until you reach 3 blast doors. Use the 3 keys in front of the doors to open them, then escape the elite mercenary base. Planet: Raxus Prime