mirror of concept art from DA:

Despite the focus on exploration the need for purely combat focused personnel resulted in the developement of dedicated fire support units.
The armor is based on construction suits that were meant to carry materials. For example the back pack, that originally was a simple storage unit for whatever task the worker had to perform was repurposed as a heavy battery/magazine. Also the ability to carry heavy weights was applied to easier deploy heavy weapons.

The lack of agility and generally slow reaction times however prevented a proposed close combat application of the unit, that would have focused on brute force. Still these units are happy to use their guns as clubs should an enemy get too close.