The BLU base was originally constructed as part of a trial to establish a multi module colony. The original trial was a failure. Despite building on what appeared to be two solid modules for a foundation the base was unsteady. After several attempts to stop the base from sinking into the planetary surface, the project was abandoned.
New techniques discovered by the I.S.A.A.C. Organization helped bring new life the the abandon base. The key discovery was the ability for astronauts to transfer supplies between modules that have been landed on the surface, but not docked together. This allows new supplies to be sent down in a cargo pod with LK Lander legs and transferred to the modules that are already on the surface.