We address the problem of attitude synchronization for multiple networked spacecraft in a setting that is completely free of any attitude parameterizations. In particular, we propose distributed cooperative control protocols that allow multiple spacecraft to align their attitudes and angular velocities through direct feedback of inertial vector measurements and angular velocity. The salient feature of this approach is that no observers or filters are utilized to recover the explicit attitude of any spacecraft in the formation. Two control protocols are presented: the first drives all spacecraft to a common attitude and angular velocity, while the second guarantees convergence to a constant reference attitude while ensuring that spacecraft align their attitudes during maneuvers. We provide rigorous analyses for both control protocols and verify the theoretical results with numerical simulations.