Yeah well...the Imperium's fear of technology (due to the 10 000 years living as Techno-barbarians), research, experimentation and scientific method, thier whole technological base sit on the STCs (Standard Template construct), which is partially why not every guardsmen in the Imperial guard doesn't have power armour and super powerful weapon.
The STCs are actually some manifacturing machine/engeneering schematics.
Back in the good ol' days before the Iron men we build (AKA robots) decided to pull a classic sci-fi moment and rebel against us, the bulk of human knowledge was stored in STCs; no one actually knew how to build things, they jsut turned the big machine at "ON" and started pumping bolters, plasma guns, melta cannons Baneblades...
Now when there's even a 0.000000000001% there's some sTc soemwhere, the Terch-Priest sends a shitlaods of troops to secure it..then spend a few hundreds of eyars studying it, then maybe, just maybe it'll be somehting that will be mass-produced to the service of the Imperium (that is, if it's not jsut brought to MArs, stored into a large vault and forgotten)