Rocket Lab is 3D printing most of their engines: <a href="http:&#x2F;&#x2F;fortune.com&#x2F;2015&#x2F;04&#x2F;17&#x2F;rocket-lab-satellites-space&#x2F;" rel="nofollow">http:&#x2F;&#x2F;fortune.com&#x2F;2015&#x2F;04&#x2F;17&#x2F;rocket-lab-satellites-space&#x2F;</a>