Who did not understand, in my settings the weight of the ship = weight of blocks = weight of components = weight of ingots The default settings are fictitious. For example: the weight of the Advanced Constructor 60T, and the components needed to create it weigh ~ 20kg All this makes a noticeable difference in the behavior of the ship with and without cargo. P.S This video shows that Empiryon has good physics, just need to properly adjust the weight and thrust of the thrusters/RCS