Well, it made it look straightforward, but not to the centre of the screen.
Here's the following code by the way (
Ship's code is commented completely out save for the
var speed = 2 # rotation speed (in radians)
var radius = 300 # desired orbit radius
var screen_size # Size of the game window.
$Ship.position = Vector2(radius, 0) # desired orbit radius
screen_size = get_viewport_rect().size
center = screen_size * 0.5
rotation += speed * delta