The weapons factories on planet Talvania were industrial sites where missiles were manufactured by the Space Pirates. They play a role in the first part of Metroid Prime: Federation Force. The Federation Force enters one of these factories in M06: Infiltration in order to destroy it. The factory appears as a set of two large domes with several smokestacks next to it, and is covered by a red grid-like force field, with gaps that can be passed through.
According to Samus Aran, the Space Pirates have secretly maintained a base on Talvania for years, establishing weapon factories all over the planet. These factories produce missiles, which they intend to use to strike the Galactic Federation. At the center of each factory is a command computer that keeps the facility's systems in top order. Hacking them would disrupt factory operations. However, each factory is guarding by an energy field that prevents Mech access. Therefore, the Force is required to infiltrate the factory without their Mechs, leaving them defenseless and weak, but faster and more spry.
The Federation Force succeeds in destroying their factory, while Samus and other squads assist in destroying all other factories. However, they miss one. The Space Pirates take advantage of this oversight and prepare several Missile Transports to strike the G.F.S. Aegis. In M10: Black Hole, the Federation Force destroys four of these Transports, as well as a fifth, Elite Transport. After the mission, Samus reports that the last factory has been destroyed.