Starfleet Technology Assessment Directorate
TheTechnology Assessment Directorate was an organization withinStarfleet which made decisions regarding the technological requirements of certain Starfleet projects, includingstarbase construction, then requested bids of independent civilian contractors and issued contracts. They generated a lengthy and complex report regarding the plans to buildStarbaseDeep Space 10 sometime prior to2376. (CoEeBook:Troubleshooting)
The TAD classifyDeep Space 9 as a "Hybrid Planar-Columnar Triradial structure". (DS9reference:Star Trek: Deep Space Nine Technical Manual)

