The project uses many well established hacks and combines them in a very clever way, without needing to re-invent the wheel.
Software Defined Radio for instance using an inexpensive DVB-T receiver hack allows to receive radio communications with a very wide bandwidth for just around 20$.
The usage of a small router TL-WR703N, which has been also whichs hardware has been well explored by the open-source community running an very customizable open-source firmware, OpenWRT, which has been around for a long time already and can be used easily on productive.
3D printing has been around for several decades and hit consumer market just a couple of years ago. There are plenty of software and hardware tools available for little money, or even suppliers on the internet, that allow cheap manufacturing of prototype parts.
SatNOGS team currently is a group of people based in a hackerspace in Athen, Greece.
You can find an illustrated assembly instruction for the mechanical parts and electronical parts here: http://satnogs.dozuki.com/