Space Ship Disaster?

Yes, a space ship disaster does open my new novel. That is not my present disaster.
Have you ever tried to design a space ship?
First is the list of things that need to be on the ship. Engines, fuel, water and air tanks plus reclaimers, cargo or passenger space, control area, two door locks, storage batteries for solar power, infirmary, bathroom and insulating hull make up a good list.
Second is the size of space ship. Since this is a short flight supply/passenger transport, it doesn't need to be huge. Since the Carduans are small, it can be small. Then it must be able to maneuver between trees and land on a rock ledge.
Oven dishes make nice oval patterns. My proposed ship is oval in shape. It has a streamlined curve over the top and flat bottom with two rollers, front and rear, for landing gear. This can provide lift flying through an atmosphere.
How tall is the ship? On my first attempt, all the storage areas except cargo/passenger space was placed under the main deck. This is similar to a cargo ship. It looks great.
This has one major flaw. The crew comes out of the door lock and suddenly descends a floor. The solution? A gang plank? An elevator? Ramps? Steps? Escalator?
None of these will work in the story. The crew must be able to step out of the door lock onto the rock ledge and back in again.
Could the storage areas be put above the main deck? There is a reason heavy things are low in a car. It puts the center of gravity low increasing the stability of the car. Top heavy cars and space ships are not smart moves.
That leaves incorporating some of these storage items into the basic floor plan. The water tank fits. The air seems to work. My problem is fitting the engines and fuel tank in.
Maybe this attempt will work and not join my pile of disaster ships.
Next comes a map of the ravine.