marked GSU are Geographically Separate Units, which although based at Diego Garcia, are subordinate to a parent unit based at another location. United States Navy Naval Computer and Telecommunications Station, Far East Detachment Diego Garcia Naval Support Facility Diego Garcia Military Sealift Command Maritime Pre-positioning Ship Squadron Two Fleet and Industrial Supply Center Diego Garcia Detachment United States Space Force Space Operations Command (SpOC) Space Delta 2 20th Space Control Squadron Detachment 2 (GSU) Space Delta 6 21st Space Operations Squadron Detachment 1 (GSU) United States Air Force Pacific Air Forces (PACAF) Eleventh Air Force 36th Wing 36th Mission Support Group Detachment 1 (GSU) Air Mobility Command (AMC) United States Air Force Expeditionary Center 515th Air Mobility Operations Wing 515th Air Mobility Operations Group 730th Air Mobility Squadron Detachment 1 (GSU) Royal Navy British Forces British Indian Ocean Territories Military contracting KBR runs base operations support services at Naval Support Facility Diego Garcia. Serco Inc., of Herndon, Virginia, operates and maintains the Ground-based Electro-Optical Deep Space Surveillance (GEODSS), which tracks deep-space satellites. Recent construction in support of US military activities on Diego Garcia has included: Black Construction/Mace International JV building a 34-metre antenna facility (expected completed by April 2021) and two new 13-metre radomes (expected completed by February 2021). Black Construction/Mace International JV repairing deep-draft wharf infrastructure (expected completed by September 2023). San Juan-Black & Veatch International Ltd. JV, of Montrose, Colorado, repairing the north parking apron (expected completed by May 2022). SJC-BVIL moving underground the power and telephone lines that run from the Navy ammunition area to the Air Force ammunition area along DG1 (expected completed by September 2022). Supplementary work at the facility includes Poole Fire Protection of Olathe, Kansas, testing and inspecting fire protection systems (June 2020 – June 2025); Jacobs/B&M JV architect-engineer services, specifically design, engineering, specification writing, cost estimating (July 2020 – July 2025); and InSynergy Engineering Inc. utility system studies (September 2020 – September 2025). References Further reading Ladwig III, Walter C., Andrew S. Erickson, and Justin D. Mikolay,"Diego Garcia and American Security in the Indian Ocean," in Carnes Lord and Andrew Erickson Rebalancing US Forces: Basing and Forward Presence in the Asia Pacific Annapolis, MD: Naval Institute Press, 2014, pp. 131–180. Ladwig III, Walter C., Urish, Daniel W., Coral, Copra, and Concrete: An Illustrated Memoir of Diego Garcia Atoll (2015). US Naval Support Facility Diego Garcia "Integrated Natural Resources Management Plan," September 2005.