Akin’s Laws of Spacecraft Design
This is definitely the wisdom of ages, but some points do show some age.<p><pre><code>    39. (alternate formulation) The three keys to keeping a new human space
    program affordable and on schedule:
       1)  No new launch vehicles.
       2)  No new launch vehicles.
       3)  Whatever you do, don&#x27;t develop any new launch vehicles.
</code></pre>
Recent SpaceX developments, Starship in particular, put some doubts on this one.