I am proceeding
The Space Construction Drone, more commonly know as a SCD, is used as a worker unit by Psionics United.
Developed by the Confederacy to be used on secret missions that would do best to avoid having any rednecks blab about it, the SCD was never put into mass use after the Confederacy fell. The research lab on Mistaff IV was abandoned, although all the designs and programming remained for the SCD and other projects.
A while later, the lab was used as refuge for a large number of ghosts that had fled the extermination of half the Ghosts in the Ghost Program. The Ghost where being hunted by a Dominion task force, and many of the Ghosts planned to escape on their own. However one, named John, managed to rally them to work together. Technopath Bart Nye managed to get some of the projects working, including the SCD which was used to barricade the doors. When the strike force attacked, a number of SCDs were destroyed however the rest where loaded onto the Hermes transport, which was eventually used by the surviving Ghosts to escape an explosion set off by them, to make the Dominion believe they died.
The SCDs continued to be used by the newly formed Psionics United both to build bases and de-construct them when moving to escape detection.
The SCD programming is based on brain waves of normal SCV pilots, with the reasoning being it would make them able to work harder, and not question any orders. However, this have given the SCDs a half sentient personality. Ghosts report SCDs chasing cattle, attempting to drink beer, and swearing when attacked. However, no one really cares because it's surprisingly funny.
The SCD is armed with a fusion cutter, which does little damage but multiple SCDs can fell low health targets. The SCD moves at the some speed as a SCV, and but accelerates even slower.
The SCD builds every building used in a PU base. It has to remain building the structure until it is complete. Once Cloaking Nanoplates is researched, the SCD can cloak. However, while constructing buildings, it is cannot cloak and the building is also not cloaked.