Manipulation in orbit represents a challenging task because the motion of the limbs can assist or even generate the angular motion of the floating base due to the conservation of centroidal momentum. Exploiting this aspect is fundamental for correctly accomplishing manipulation tasks in multi-limbed robotic systems employed in orbit. This short paper proposes a whole-body motion controller for teleoperation or visual serving that can exploit collision-free null-space motions of the limbs to generate the desired angular motion of the base in the absence of contacts and gravity. The results are demonstrated through kinematic and dynamic simulations using the model of a humanoid robot with multiple Degrees of Freedom.