Based on what I’ve learned from games like KSP and Spaceflight Simulator, anything in orbit will “roll” relative to the earth (ex if something is pointed away from
Earth at one point in orbit at the opposite point of its orbit it will point directly at Earth). Obviously a satellite would need to be always pointing toward earth, so how would it? I’ve also noticed this with the ISS when I watched a timelapse that was taken from the cupola.
In: Engineering
In addition to the initial spin mentioned by the first comment, most satellites have small manuevering thrusters to keep themselves in the proper orbit and maintain their orientation, so these would be used as needed.
You could take that satellite as you describe, and gently spin it in the same direction as it is orbiting. If you get the spin rate just right then the same side will keep facing the Earth. Conveniently there is no reason for it to stop spinning, so it will keep facing the right way. There are various mechanisms that you can use to adjust the spin: thrusters and reaction wheels are common.
They just spin around their axis with the same period as their orbit. Since their is very little to no atmosphere to slow them down a tiny initial kick is enough to get them spinning for a while.
[edit] They spin themselves using RCS or gyros.
Some of them have long booms, one points down and the other away, and the differential pull cause by gravity/tides keeps them aligned that way.
Latest Answers