This is balance bug:
Life Support modules -> In the shipbuilder, the costs are listed properly, but (at least with Basic Support, maybe others) you're charged the cost rather than the size when you add the component, as long as you can still fit the component based on the size.
Specifically, the Basic Support Module is cost 2, size 4, but when you add it and you're say at 49/55 or 51/55, it only consumes 2 space points, When you're at say 53/55, it'll say the module's too big.
This is another bug:
Also, I built some fast colony ships and explorer ships (with Hyperdrive Plus engines) in a previous game (Beta 3, I think), under the Drath. When I started this game, also as the Drath, I was able to upgrade the ship designs that carried over from my old game (without removing the components) and they suddenly had a lot more space, as if the engines only had been removed. I'm not sure of the exact math.
This allowed me to make several illegal designs. I had a colony ship with 7 engines on it and and explorer ship with 12. This was without researching new techs. Removing the engines and then adding them back on seemed to behave properly, though. (ie no illegal stuffing.)
Later on the design costs fixed themselves (due to miniaturization, maybe?) and so I couldn't upgrade them anymore - not that I had to. Also, the bug existed only as long as I didn't remove the engines and replace them with something else.
