&gt; The thrust vector has stable orientation relative to the rocket (if you don&#x27;t gimbal)<p>This is what makes your argument moot - because they <i>do</i> gimbal, and the gimbaling is what creates the moment&#x2F;torque. In a way that <i>is</i> very nearly analogous to twisting your hand around slightly to balance a broomstick.<p>&gt; The yardstick is unstable in inclination if it isn&#x27;t vertical. The rocket is unstable in horizontal position if it isn&#x27;t vertical.<p>The rocket is unstable in position <i>and</i> inclination (attitude). So you&#x27;re right that there&#x27;s more to it, but it&#x27;s still the inverted pendulum problem for attitude, plus the rocket formulas for translation and added constraints of landing location. Are you saying Bezos is lying in this post when he explicitly says &quot;When you do a vertical landing, you’re solving the classic inverted pendulum problem&quot;? He would know, and I don&#x27;t see a reason for him to lie about it.