&gt; And the vertical landing architecture scales extraordinarily well. When you do a vertical landing, you’re solving the classic inverted pendulum problem, and the inverted pendulum problem gets a bit easier as the pendulum gets a bit bigger. Try balancing a pencil on the tip of your finger. Now try it with a broomstick. The broomstick is simpler because its greater moment of inertia makes it easier to balance.<p>They&#x27;re specifically doing smaller rockets to tackle the inverted pendulum problem first, then they will scale up.  They see that as the bigger challenge, and may greatly affect the design of larger orbital rockets which have a great deal of research available to draw from for other challenges they run into. In the article they say that one of their major solutions is a gimbaling engine, which I imagine is something you would have to design a larger rocket around, rather than add in after the fact.