The Atrenids are masters at creating technology.
Atrenid spaceships are often large, designed for scientific purposes. Standard craft have room for biological facilities, tech bays, historical bunkers, labs, and much more.
The first fleet of five ships were very large, designed to hold the entire Atrenid race. Each had to carry around a billion individuals, so the vessels were 70km long. Though initially poorly armed and armoured, they were upgraded and refitted extensively as the Atrenids entered galactic society. They have been equipped with an enormous railgun going along their length, batteries of lasers and flak guns, and powerful defenses. They are maintained by enormous teams of engineers.
Fighting ships are packed to the limits with assorted defenses. The production of military vessels is low on the Atrenids' priorities, given the number of heavily-armed allies they have and their emphasis on exploration and research, but they do build one class of spacecraft. These are the Kawar-class battleships, which are 3.4km long, with powerful repulsors, notoriously reliable and effective fusion engines, and have many weapons including lasers and mass drivers.
The Atrenids maintain a standing fleet of fifty-two battleships. Their flagship is the Endeavour.
Atrenids make a unique type of armor that is very flexible. It covers the entire body and is resilient to all types of standard firearms.
Atrenids have developed exploratory probes, not unlike those of the Salsenes.