Ship Concept Sketches

We had to come up with 'thumbnail' concepts of spaceships. An assignment for my 4th year.
I tried to do thumbnails but...the majority ended up being bigger.....and detailed. We were to make a 3D model of our final design, so I did want to avoid intricate details....but yea...
Was inspired by alot of airships, rather than spaceships >.>
Sorry I'm just not good with sci-fi stuff T_T