So I upgraded my Scout Mk 2 to a Mk 3, not realising that the Stellar Support module only fits into the Mk 3 design once before space runs out.
Okay so, granted, Stellar Support is quite a big leap up in terms of how much range you get for the space you use, but two of the Environmental Support components beat one of Stellar Support. 
One suggestion comes to mind here. Instead of making components like these a fixed size for a fixed bonus, allow the player to scale life support components according to the best ratio of mass to life support available with current technology.