The big vents about midway up the vehicle are gaseous depressurization vents for the methane and liquid oxygen tanks; the RCS (reaction control system) that's d

The big vents about midway up the vehicle are gaseous depressurization vents for the methane and liquid oxygen tanks; the RCS (reaction control system) that's designed to provide torque has thrusters at the nose and tail (to maximize the length of the lever arm.) https://youtu.be/6iBnXy1ag8A?t=109 https://youtu.be/6iBnXy1ag8A?t=109