Observational Drawing

Above is an observational drawing I made of an image of a spaceship, and the source image I used with which to draw it. Spaceships are relevant to my final piece, so this is why I chose this to draw.
There weren't any real complications, and drawing it was relatively simple, although the proportions were difficult to stick to accurately.
I tried to adhere to the Rule of Thirds in this image. I feel I could have done so better, as due to a mistake with proportions, the drawing ended up looking closer to the centre than I'd liked. I will try to avoid this next time.
Since I plan to use a design for a spaceship as my final piece, I will continue to draw different designs of ship throughout the project to attempt to develop my drawing skills in this field.