all in all rev pretty good! especially not only for new software but also from what i've seen your first big venture into this TYPE of image yknow ?
if you wanted a more "slick" image you could clean and sharpen the edges of the ship. or even make a motion blur - i don't know much about your software.
so congrats ! your composition is fairly good. star placement good. planets are nice and well placed. you give us a little of the feel of open "space" in good proportion at the bottom. keep creating my friend - i already KNOW you've got alot of imagination ! keep using it!