As i am watching live-stream of Demo-2 mission,the trajectory of a capsule is shown curved(like sin wave). In other words, why their trajectory isn't along longitude so that in 2D, the path followed by the 'Endeavour' becomes straight. Mind you I am not talking about this question.
My prediction: Its because of earth rotation. The main reason is due to the 23.5 degree tilt of Earth's spin axis. So even the spacecraft is moving straight, its trajectory will be always zig-zag in 2D. To have straight path in 2D, it must use its propulsion to compensate the zig-zagness of its path. Are my claims correct?