You can edit the parameters of some modules in KSP to make them lighter, or change their performance - I hack together a more viable engine and landing gear for a Mun landing. I also show that exceeding the engine's limits can cause odd problems. So, for details: I Take the LiquidEngine2 and make LiquidEngine3 arttachrules get changed from 1,0,1,0,0 to 1,1,1,1,0 so I can attach stuff to the side of the engine mass gets reduced from 2.0 to 0.5 maxthrust gets reduced to 40 from 175 fuelconsumption gets cut from 7 to 1.5 The Lateral decouplers which I use for langing legs get their mass reduced from 0.4 to 0.1