Hull size and mass

I was reading through this section and had to comment on something that I found was missing, in your description you made no mention about the required space needed aboard the ship for its fuel payload. While the engines might be mounted externally on pylons or struts and thus do not take up space in configuing the mass of the ship, fuel (particularly chemical fuel) takes up a lot of space, and should add to the initial cost of the ship for the amount of space that it displaces if not for the fuel itself.<br /><br />Space and fuel costs might become a major determining factor in determining the engine types that are purchased, with cheap chemical rockets being not so readilly chosen because of the largue volume of space required for fuel payload, while atomic or ion engines might be more economical. And of course if you add scoops to streamlined ship to enable them to suck up fuel from gas giants, Ion drives might be even more popular than atomic drives.<br /><br /><br />