# Why does the ISS rotate exactly once per orbit?

Looking at the HDEV experiment, one can see that the orientation of the ISS is always the same with respect to the Earth. This means that the ISS must rotate exactly once per orbit (like the Moon tidally locked in orbit around the Earth); otherwise one would not see always the 'same' surface area of the Earth filling the video.

Why is this the case? Because of communication purposes? And how is this locked rotation being achieved?

• – BowlOfRed Oct 16 '15 at 5:17

• I failed to find the exact phrase Torque-Equivalent Attitude in a google search. But I did find torque equilibrium attitude. Is this what you are referring to? – Ruslan Oct 16 '15 at 6:43