The satellite and its work done

[HLAung]

If the starting and ending points are the same, there is no displacement.
If there is no displacement, no matter how much energy is exerted, work is not done.

So, is an artificial satellite orbiting the Earth with the same starting and ending points not working?

In my opinion, in such a problem, we should think about
1. Can the satellite perform its assigned task?
2. If it is functioning, the solar energy it receives, utilizes and stores while orbiting the Earth is its work done.
3. If it is orbiting without functioning, work is not done (Work done is zero.).

 

[PeroK]

An object in a circular orbit has constant kinetic and potential energy, so the Earth's gravitational force does no work on it.

I don't see the relevance of solar energy.

 

[Borek]

Define "work done".

Just because I am lying motionless in bed doesn't mean I haven't done any mental work. I could solve some pesky problem, or write a poem.