Question

What is the difference between flying around the earth and orbiting the earth on the ISS? Which do you think takes more energy, and why?

Answer 1

You can't fly around the earth because in space around the earth there is earth gravity which will attracts you towards the earth and you will fall into the earth but you can fly on the earth because if you want to fly you need atmosphere which is on the earth .That's why by applying proper thrust you can fly on Earth .

Orbiting means your going to orbit around the earth in space with particular time period and you don't need any energy to orbiting around the earth because here the gravitational Force of Earth will going to balance your centripetal force (it is force acting when you orbit around the earth in circular orbit) and hence you don't need any energy to orbiting around the earth but while flying on Earth you need energy .

And hence flying takes energy and on other hand orbiting around the earth doesn't require energy .