{{short description|U.S. Space Force space domain awareness delta}} {{Use dmy dates|date=July 2021}} {{Use American English|date=July 2021}} {{Infobox military unit | unit_name = Mission Delta 2 | image = Emblem of Space Delta 2.png | caption = Mission Delta 2 emblem | start_date = {{Start date and age|1942|02|01|df=yes}}<br />''as 21st Bombardment Group''<ref name=afhra /> ---- {{Start date and age|2020|07|24|df=yes}}<br />''as Space Delta 2'' | country = {{flagu|United States}} | allegiance = | branch = {{space force|United States}} | type = [[Delta (U.S. Space Force)|Delta]] | role = [[Space domain awareness]] | size = 380 personnel<ref>{{cite AV media |people= |date=1 April 2021 |title=Leading the Guardians of Today |trans-title= |medium=YouTube |language= |url=https://www.youtube.com/watch?v=AjplFBsEksw |access-date=26 July 2021 |archive-url=https://web.archive.org/web/20210726115212/https://www.youtube.com/watch?v=AjplFBsEksw |archive-date=26 July 2021 |format= |time=1:42 |location= |publisher= |id= |isbn= |oclc= |quote= |url-status=live }}</ref> | command_structure = {{no wrap|[[File:Space Operations Command emblem.png|25px]] [[Space Operations Command]]}} | current_commander = | garrison = [[Peterson Space Force Base]], [[Colorado]], U.S. | garrison_label = Headquarters | ceremonial_chief = | colonel_of_the_regiment = | nickname = ''Sentinels''<ref name="video">{{Cite web|url=https://www.dvidshub.net/video/787528/delta-2-mission-video|title=Delta 2 Mission Video|website=DVIDS|access-date=23 July 2021|archive-date=23 July 2021|archive-url=https://web.archive.org/web/20210723122022/https://www.dvidshub.net/video/787528/delta-2-mission-video|url-status=live}}</ref> | patron = | motto = | colors = | march = | mascot = | battles = [[File:World War II - American Campaign Streamer (Plain).png|200px]]<br />[[American Theater (World War II)|Antisubmarine, American Theater]]<br />[[File:Streamer APC.PNG|200px]]<br />[[Air raids on Japan|Air Offensive, Japan]]<br />[[File:Global War on Terrorism Service Medal streamer.png|200px]]<br />Global [[war on terror]]ism<ref name=afhra /> | decorations = [[File:Streamer PUC Army.PNG|200px]]<br />[[Distinguished Unit Citation]]<br />[[File:US Air Force Outstanding Unit Award - Stremer.jpg|200px]]<br />[[Air Force Outstanding Unit Award]]<ref name=afhra /> | notable_commanders = | anniversaries = <!-- Commanders --> | commander1 = [[Colonel (United States)|Col]] Barry A. Croker | commander1_label = Commander | commander2 = [[Lieutenant colonel (United States)|Lt Col]] Scott D. Munn<ref name="feature">{{Cite web|url=https://www.peterson.spaceforce.mil/News/Article/2564700/space-delta-2-monitors-deep-space/|title=Space Delta 2 monitors deep space|website=[[Peterson Air Force Base]]|last=Brady|first=Stephen|date=7 April 2021|access-date=30 June 2021|archive-date=9 July 2021|archive-url=https://web.archive.org/web/20210709181817/https://www.peterson.spaceforce.mil/News/Article/2564700/space-delta-2-monitors-deep-space/|url-status=live}} {{PD-notice}}</ref> | commander2_label = Deputy Commander | commander3 = [[Chief Master Sergeant|CMSgt]] Leomel I. Abueg<ref>{{cite web | url=https://www.petersonschriever.spaceforce.mil/SpaceDelta2/ | title=Space Delta 2 }}</ref> | commander3_label = Senior Enlisted Leader | website = {{URL|https://www.peterson.spaceforce.mil/Units/Space-Delta-2/}} <!-- Insignia --> | identification_symbol = [[File:Space Delta 2 guidon.svg|150px]] | identification_symbol_label = Guidon }}
'''Mission Delta 2''' ('''MD2''') is the [[United States Space Force]]'s [[space domain awareness]] [[Space Delta|delta]], headquartered at [[Peterson Space Force Base]], Colorado. Mission Delta 2 tracks and monitors all human made objects from [[low Earth orbit]] to [[geosynchronous orbit]] and further out to [[outer space|deep space]]. It also partners with the [[National Oceanic and Atmospheric Administration]] to provide weather satellite observation for the U.S. Armed Forces. It consists of the [[15th Space Surveillance Squadron]], [[18th Space Defense Squadron]], [[19th Space Defense Squadron]], and [[20th Space Surveillance Squadron]].<ref>{{Cite web|url=https://www.peterson.spaceforce.mil/Newsroom/News/Article-Display/Article/2564700/space-delta-2-monitors-deep-space/|title=Space Delta 2 monitors deep space|website=Nellis Air Force Base|access-date=4 June 2022|archive-date=4 June 2022|archive-url=https://web.archive.org/web/20220604092707/https://www.peterson.spaceforce.mil/Newsroom/News/Article-Display/Article/2564700/space-delta-2-monitors-deep-space/|url-status=live}}</ref><ref name="factsheet">{{Cite web|date=24 July 2020|title=Delta 2 Factsheet|url=https://www.peterson.spaceforce.mil/Portals/15/Delta2_factsheet.pdf|website=[[Peterson Air Force Base]]|url-status=live|access-date=24 June 2021|archive-date=15 November 2020|archive-url=https://web.archive.org/web/20201115191029/https://www.peterson.spaceforce.mil/Portals/15/Delta2_factsheet.pdf}} {{PD-notice}}</ref>
Mission Delta 2 was originally established on 1 February 1942 as the '''21st Bombardment Group''' ('''21 BG'''), flying the B-25 Mitchell and B-26 Marauder in antisubmarine patrols during [[World War II]]. After the 21 BG inactivated in 1943, the '''21st Fighter Group''' ('''21 FG''') was activated in 1943 in Hawaii, flying the P-39 Airacobra, P-38 Lightning, and P-51 Mustang during the [[Battle of Iwo Jima]] and escorting bombers during air raids on Japan until the 21 FS was inactivated in 1946. The 21st was reactivated again in 1952 as the '''21st Fighter-Bomber Group''' ('''21 FBG''') under the 21st Fighter-Bomber Wing and flying the F-86 Sabre, deploying to support NATO forces in France during the [[Cold War]] before inactivating in 1958. Although the group would be redesignated the '''21st Tactical Fighter Group''' ('''21 TFG''') in 1985, it would not be reactivated until 1991 as the '''21st Operations Group''' ('''21 OG'''), when it briefly was reactivated under the 21st Wing, providing air defense for Alaska flying the F-15C and F-15E, before inactivating later that year. The 21st Operations Group was reactivated under [[Air Force Space Command]]'s [[21st Space Wing]] in 1992 and provided missile warning, space surveillance, and space control forces. On 24 July 2020, it was redesignated as Space Delta 2 and transferred from the Air Force to the Space Force on 21 October 2020.<ref name=afhra /> On 31 October 2024 it was redesignated Mission Delta 2 and gained sustainment responsibilities, along with organic cyber defense and intelligence forces.<ref>{{Cite web | title=Two DELs transition to fully-integrated Mission Deltas > Space Operations Command (SpOC) > Article Display | url=https://www.spoc.spaceforce.mil/News/Article-Display/Article/3952582/two-dels-transition-to-fully-integrated-mission-deltas | archive-url=https://web.archive.org/web/20241106022819/https://www.spoc.spaceforce.mil/News/Article-Display/Article/3952582/two-dels-transition-to-fully-integrated-mission-deltas | access-date=2025-08-06 | archive-date=2024-11-06}}</ref>
==History== ===Anti-submarine patrols in the American Theater=== [[File:21 Bomb Group B-26 Marauders.jpg|thumb|B-26 Maruder medium bombers of the 21st Bombardment Group at MacDill Field.]] {{Gallery | title = 21st Bombardment Group (Medium) squadrons | align = center | width=120 | captionstyle = text-align:center; | File:313 Bombardment Sq emblem.png|[[313th Bombardment Squadron]] | File:314 Bombardment Sq emblem.png|314th Bombardment Squadron | File:398 Bombardment Sq (M) emblem.png|[[398th Bombardment Squadron]] }}
On 1 February 1942, the 21st Bombardment Group (Medium) was activated at [[Bowman Field (Kentucky)|Bowman Field]], Kentucky under the [[United States Army Air Forces]]' [[Air Force Combat Command]], flying the [[North American B-25 Mitchell]] [[medium bomber]]. It consisted of the [[98th Expeditionary Air Refueling Squadron|8th Reconnaissance Squadron]] (later redesignated the 398th Bombardment Squadron), [[313th Bombardment Squadron]], [[314th Bombardment Squadron]], and [[315th Bombardment Squadron]]. On 6 February 1942, the 21st Bombardment Group moved to [[Jackson Army Air Base]], Mississippi, serving as an operational training group. On 11 March 1942, it was realigned under the [[3rd Air Force]]'s [[III Bomber Command]] and on 21 April 1942 moved to [[Columbia Army Air Base]]. On 2 May 1942, it was briefly reassigned from III Bomber Command to [[XII Bomber Command]], before being regained by III Bomber Command on 8 May 1942 and moved to [[Key Field]], Mississippi on 24 May 1942. On 24 June 1942, the 21st Bombardment Group moved to [[MacDill Field]], Florida and converted to [[Martin B-26 Marauder]] medium bombers. While stationed at MacDill Field, the group conducted [[antisubmarine warfare|anti-submarine patrols]] in the Caribbean Sea, participating in the [[American Theater (World War II)|American Theater]] of [[World War II]]. On 10 October 1943, the 21st Bombardment Group was inactivated.<ref name=heritage>{{Cite web|url=https://www.peterson.spaceforce.mil/Portals/15/documents/History/21%20SW%20Heritage%20Pamphlet_7Jun17_1530.pdf?ver=2017-06-22-100413-633|title=21st Space Wing Heritage Pamphlet|access-date=25 May 2020|archive-url=https://web.archive.org/web/20191225191807/https://www.peterson.af.mil/Portals/15/documents/History/21%20SW%20Heritage%20Pamphlet_7Jun17_1530.pdf?ver=2017-06-22-100413-633|archive-date=25 December 2019|url-status=live}}</ref><ref name=afhra>{{Cite web|url=https://www.dafhistory.af.mil/About-Us/Fact-Sheets/Display/Article/2920784/space-delta-2-spoc/|title=Space Delta 2 (SpOC)|work=Air Force Historical Research Agency |access-date=25 March 2022|archive-date=4 June 2022|archive-url=https://web.archive.org/web/20220604092707/https://www.afhra.af.mil/About-Us/Fact-Sheets/Display/Article/2920784/space-delta-2-spoc/|url-status=live}}</ref>
===Bomber escort and fighter operations in the Pacific Theater=== [[File:21st Fighter Group P-51s at Iwo Jima - 1945.png|thumb|21st Fighter Group P-51 Mustangs on Iwo Jima.]] {{Gallery | title = 21st Fighter Group squadrons | align = center | width=120 | captionstyle = text-align:center; | File:46 Pursuit Sq emblem.png|[[46th Fighter Squadron]] | File:72d Fighter Squadron.png|[[72nd Fighter Squadron]] | File:531st Fighter Squadron - World War II emblem.png|[[531st Fighter Squadron]] }}
On 31 March 1944, the 21st Fighter Group, Two Engine, was activated on 21 April at [[Wheeler Field]], Hawaii and assigned to the US Army Air Forces, Central Pacific Area before being realigned under [[Seventh Air Force]]'s [[VII Fighter Command]] on 24 April 1944. The 21st Fighter Group consisted of the [[46th Fighter Squadron]], [[72nd Fighter Squadron]], and [[531st Fighter Squadron]] and flew the [[Bell P-39Q Airacobra]]. Tasked with providing [[air defense]] over the Hawaiian Islands, the 21st Fighter Wing was realigned under the [[7th Air Division|7th Fighter Wing]] on 3 July 1944 and began upgrading to the [[Lockheed P-38 Lightning|Lockheed P-38J/L Lightning]] in September 1944. In October 1944, the 21st Fighter Group switched aircraft again, flying the [[North American P-51 Mustang]] and transferring to [[Mokuleia Field]], Hawaii on 13 October 1944. On 10 November 1944, the 21st Fighter Group was realigned under the VII Fighter Command, but remained attached to the 7th Fighter Wing until 28 February 1945.<ref name=heritage/>
[[File:21st Fighter Group P-51s at Iwo Jima 2 - 1945.png|thumb|21st Fighter Group P-51 Mustangs on Iwo Jima.]]
In February 1945, the 21st Fighter Group was directly resubordinated under the VII Fighter Command and transported by ships to Iwo Jima, arriving at [[Central Field (Iwo Jima)|Central Field]] on 25 March 1945. On the Morning of 26 February 1945, the elements of the 21st Fighter Group was attacked by [[Imperial Japanese Army]] soldiers on the ground. Fighting alongside a contingent of [[U.S. Marines]], the airmen killed 250 Japanese soldiers in tent-to-tent fighting, with fourteen 21st Fighter Group airmen killed and 50, including the group commander, Colonel [[Kenneth R. Powell]], were wounded. Following the engagement on the ground, the 21st Fighter Group provided [[close air support]] for the remainder of the [[Battle of Iwo Jima]].<ref name=heritage/>
Following the island's capture, the 21st Fighter Group began conducting long-range [[bomber escort]] missions, with the first occurring on 7 April 1945, where P-51 Mustangs from the group escorted B-29 Superfortress heavy bombers striking the [[Nakajima Aircraft Company]] in Tokyo. This mission was the first time bombers over Japan were accompanied by escort fighters and was the longest over-water fighter escort mission to that point during World War II. On 16 July 1945, the group transferred to Iwo Jima's [[South Field (Iwo Jima)|South Field]] and flew its last combat mission over Japan on 14 August 1945. For its raid over Nakajima Aircraft Company, the 21st Fighter Group was awarded the [[Distinguished Unit Citation]]. After the end of World War II, the 21st Fighter Group transferred to [[Isely Field]], Saipan on 4 December 1945 and then to [[Northwest Field (Guam)|Northwest Field]], Guam on 17 April 1946. The 21st Fighter Group was inactivated on 10 October 1946.<ref name=heritage/>
===NATO deployment to France=== {{Gallery | title = 21st Fighter-Bomber Group squadrons | align = center | width=120 | captionstyle = text-align:center; | File:72d Fighter-Bomber Squadron - Emblem.png|[[72nd Fighter-Bomber Squadron]] | File:416th Fighter-Bomber Squadron - emblem.png|[[416th Fighter-Bomber Squadron]] | File:531st Fighter Squadron - World War II emblem.png|[[531st Fighter-Bomber Squadron]] }}
[[File:72d Fighter-Bomber Squadron - North American F-86F-35-NA Sabre - 52-5233.jpg|thumb|F-86F Sabre of the [[72nd Fighter-Bomber Squadron]]]]
On 1 January 1953, the 21st was reactivated as the 21st Fighter-Bomber Group at [[George Air Force Base]], California under the [[21st Fighter-Bomber Wing]]. Following the end of World War II, the [[wing (military unit)|wing]] replaced the [[group (military unit)|group]] as the primary unit of organization within the Air Force. Initially organized under [[Tactical Air Command]]'s [[Ninth Air Force]], the 21st Fighter-Bomber Group consisted of its World War II [[72nd Fighter-Bomber Squadron]] and [[531st Fighter-Bomber Squadron]], adding the [[416th Fighter-Bomber Squadron]]. Initially flying the [[F-51 Mustang]] fighter, within six months of activation, the 21st Fighter-Bomber Group had transitioned to the [[North American F-86F Sabre]], a first-generation jet fighter. In September and October 1953, the 21st Fighter-Bomber Group participated in a special arctic warfare program at [[Eielson Air Force Base]], Alaska. Following the completion of this exercise, it sent six F-86s to participate in Project Willtour, which consisted of an 11,000 mile tour of twelve Central, Caribbean, and South American countries. In April and May 1954, it participated in Operation Boxkite at [[North Auxiliary Airfield|North Field]], South Carolina, testing the ability for a tactical wing to deploy to a forward location and sustain thirty days of combat operations.<ref name=heritage/>
Following the completion of these exercises, on 22 June 1954, the [[United States Secretary of the Air Force|Secretary of the Air Force]] announced that the 21st Fighter-Bomber Wing, including the 21st Fighter-Bomber Group, would be deployed to [[Chambley Air Base]], France, under [[Twelfth Air Force]] and the [[North Atlantic Treaty Organization]] to defend against the [[Warsaw Pact]] and [[Soviet Union]]. While the 21st Fighter-Bomber Wing's personnel moved in four tranches across air, land, and sea transport, the 21st Fighter-Bomber Group's F-86s flew directly, stopping in Labrador, Greenland, Iceland, and Scotland. The 21st Fighter-Bomber Group officially was stationed at Chambley Air Base on 12 December 1954, however the airfield could not handle the jet fighters until it was upgraded by Air Force engineers in June 1956. The flying elements of the group operated in the interim out of a variety of airfields in the French countryside.<ref name=heritage />
One of the most notable pilots in the 21st Fighter-Bomber Group was then-First Lieutenant [[Michael Collins (astronaut)|Michael Collins]], who would later become a [[NASA]] astronaut, flying the [[Gemini 10]] and [[Apollo 11]] missions, before retiring from the Air Force as a major general.<ref name=heritage/>
The 21st Fighter-Bomber Group conducted close air support training with [[United States Army Europe]] land forces and took first place at the [[United States Air Forces in Europe]]'s gunnery meet at [[Wheelus Field]], Libya. In 1955, the 21st Fighter-Bomber Group participated NATO's [[Carte Blanche (1955 NATO exercise)|Carte Blanche]] atomic warfare exercise and took second place at [[Nellis Air Force Base]]'s gunnery exercise in 1956. The unit also won the United States Air Forces in Europe award for tactical proficiency in 1957. On 8 February 1958, the 21st Fighter-Bomber Group and 21st Fighter-Bomber Wing were inactivated.<ref name=heritage/>
===Alaskan air defense operations=== [[File:US F-15s and Soviet MiG-29s over Alaska 1989.JPEG|thumb|43rd Tactical Fighter Squadron F-15s escort Soviet Air Forces MiG-29s on their visit to America.]] {{Gallery | title = 21st Operations Group squadrons | align = center | width=120 | captionstyle = text-align:center; | File:21st Operations Support Squadron.PNG|[[21st Operations Support Squadron]] | File:43rd Fighter Squadron.png|[[43rd Fighter Squadron]] | File:54th Fighter Squadron.jpg|[[54th Fighter Squadron]] | File:90 Fighter Sq.jpg|[[90th Fighter Squadron]] }} While the 21st Wing would continue, Air Force policy on operations groups resulted in the 21st Fighter-Bomber Group remaining inactive for the following decades. In 1985, it was redesignated as the 21st Tactical Fighter Group, but not activated until 25 September 1991 as the 21st Operations Group under the [[21st Wing]] at [[Elmendorf Air Force Base]], Alaska. It briefly consisted of the [[21st Operations Support Squadron]], [[43rd Fighter Squadron]], [[54th Fighter Squadron]], and [[90th Fighter Squadron]] under [[Alaskan Air Command]] and supporting [[North American Aerospace Defense Command]]. The 43rd Fighter Squadron and 54th Fighter Squadron flew the [[McDonnell Douglas F-15C Eagle]], while the 90th Fighter Squadron flew the [[McDonnell Douglas F-15E Strike Eagle]]. Following the 21st Operations Group's activation, the Air Force implemented a program that directed that each base would have one wing and one commander. The 21st Wing and [[3rd Wing]] shared Elmendorf Air Force Base, resulting in the 21st Wing, and 21st Operations Group's inactivation on 19 December 1991.<ref name=heritage/>
===From space surveillance to space control=== {{Gallery | title = 21st Operations Group space warning squadrons | align = center | width=120 | captionstyle = text-align:center; | File:3d Command and Control Squadron.PNG|[[3rd Command and Control Squadron]] | File:2d Space Warning Squadron.jpg|[[2nd Space Warning Squadron]] | File:4th Space Warning Squadron.png|[[4th Space Warning Squadron]] | File:5th Space Warning Squadron.jpg|[[5th Space Warning Squadron]] | File:6th Space Warning Squadron.jpg|[[6th Space Warning Squadron]] | File:7th Space Warning Squadron.PNG|[[7th Space Warning Squadron]] | File:8th Space Warning Squadron.png|[[8th Space Warning Squadron]] | File:9th Space Warning Squadron.PNG|[[9th Space Warning Squadron]] | File:10th Space Warning Squadron.jpg|[[10th Space Warning Squadron]] | File:11th Space Warning Squadron, pre-2023 emblem.png|[[11th Space Warning Squadron]] | File:12th Space Warning Squadron.png|[[12th Space Warning Squadron]] | File:13th Space Warning Squadron.png|[[13th Space Warning Squadron]] }} [[File:PAVE PAWS Radar, Beale AFB, USA.jpg|thumb|[[PAVE PAWS]] radar at [[Beale Air Force Base]].]] On 15 May 1992, the 21st Operations Group was reactivated alongside the [[21st Space Wing]] at [[Peterson Air Force Base]] under [[Air Force Space Command]], with the 21st Operations Group specifically absorbing the responsibilities of the former [[1st Space Wing]]. The 21st Operations Group's primary mission was [[missile warning]]. It operated the [[Defense Support Program]] missile warning constellation, which was flown by the [[2nd Space Warning Squadron]] at [[Buckley Air National Guard Base]] and the [[5th Space Warning Squadron]] at [[RAAF Base Woomera|Woomera Air Station]], Australia, while the [[4th Space Warning Squadron]] operated the Mobile Ground Station from [[Holloman Air Force Base]], before transferring the mission to the [[Air National Guard]]'s [[137th Space Warning Squadron]] in 1997. The [[11th Space Warning Squadron]] was activated in 1994 at [[Falcon Air Force Base]] to operate the Attack and Launch Early Reporting to Theater (ALERT) missile warning system.<ref name=heritage/>
The 21st Operations Group also inherited three [[Ballistic Missile Early Warning System]] (BMEWS) radars, operated by the [[13th Space Warning Squadron]] at [[Clear Air Force Station]], Alaska, [[12th Space Warning Squadron]] at [[Thule Air Base]], Greenland, and a [[Royal Air Force]] operated radar at [[RAF Fylingdales]]. As the BMEWS radars had been in operation since the 1960s, the sites were in the process of being upgraded to the [[Solid State Phased Array Radar System]] (SSPAR), with Thule Air Base's being upgraded in 1987, RAF Fylingdales' in 1992, and Clear Air Force Station's in 2001. The 21st Operations Group also inherited the [[PAVE PAWS]] radars operated by the [[6th Space Warning Squadron]] at [[Cape Cod Air Force Station]], [[7th Space Warning Squadron]] at [[Beale Air Force Base]], [[8th Space Warning Squadron]] at [[Eldorado Air Force Station]], and [[9th Space Warning Squadron]] at [[Robins Air Force Base]]. The last ground-based missile warning radar operated by the 21st Operations Group was the [[AN/FPQ-16 PARCS]] at [[Cavalier Air Force Station]] and operated by the [[10th Space Warning Squadron]]. Following the end of the Cold War and the implementation of budget cuts, the radars and squadrons as Eldorado Air Force Station and Robins Air Force Base were inactivated.<ref name=heritage/>
{{Gallery | title = 21st Operations Group space surveillance squadrons | align = center | width=120 | captionstyle = text-align:center; | File:1st Space Control Squadron.png|[[1st Command and Control Squadron]] | File:2d Command and Control Squadron.jpg|[[2nd Command and Control Squadron]] | File:1st Space Surveillance Squadron.PNG|[[1st Space Surveillance Squadron]] | File:3d Space Experimentation Squadron Patch.jpg|[[3rd Space Surveillance Squadron]] | File:4 SPCS.jpg|[[4th Space Surveillance Squadron]] | File:5th Space Surveillance Squadron.png|[[5th Space Surveillance Squadron]] | File:17th Space Surveillance Squadron.png|[[17th Space Surveillance Squadron]] | File:18th Space Surveillance Squadron.PNG|[[18th Space Surveillance Squadron]] | File:19th Space Surveillance Squadron.PNG|[[19th Space Surveillance Squadron]] | File:20th Space Control Squadron Emblem.jpg|[[20th Space Surveillance Squadron]] | File:21st Crew Training Squadron.png|21st Crew Training Squadron | File:21st Operations Support Squadron.PNG|[[21st Operations Support Squadron]] }} [[File:Ground-Based Electro-Optical Deep Space Surveillance (GEODSS) in Diego Garcia.jpg|thumb|[[Ground-Based Electro-Optical Deep Space Surveillance]] (GEODSS) site at the [[Maui Space Surveillance Complex]].]]
The 21st Operations Group also operated a network of [[space surveillance]] radars across the Earth. The [[AN/FPS-79]] was operated by the [[19th Space Surveillance Squadron]] at [[Pirinçlik Air Base]], Turkey. The radar and its predecessor had been conducting operations since 1955 and monitored space and missile launches out of the [[Soviet Union]] and Russia, including the launch of [[Sputnik]], [[Vostok programme|Vostok]], and events related to [[Operation Desert Storm]] until it was inactivated in 1999. The 21st Operations Group also gained the [[20th Space Surveillance Squadron]], which had operated the [[AN/FPS-85]] at [[Eglin Air Force Base]] since 1988. Detachments of the [[18th Space Surveillance Squadron]] operated the [[Ground-based Electro-Optical Deep Space Surveillance]] System (GEODSS), with Detachment 1 operating at [[Socorro, New Mexico]], Detachment 2 at [[Diego Garcia]], and Detachment 3 at the [[Maui Space Surveillance Complex]], replacing the older network of [[Baker-Nunn camera]]s. Detachment 4 operated the Transportable Optical System (TOS) at [[Morón Air Base]] starting in September 1998, and was renamed the Moron Optical Surveillance System (MOSS) in 1999. In November 2005, Morón Air Base would receive the El Raven telescope and in June 2006 it would gain the RO4 high-volume superior resolution camera. The 21st Operations Group also operated two passive radars, with the Deep Space Tracking System antennas operated by the [[3rd Space Surveillance Squadron]] at [[Misawa Air Base]], Japan and [[5th Space Surveillance Squadron]] at [[RAF Feltwell]]. The Low Altitude Space Surveillance System was operated by the [[4th Space Surveillance Squadron]] at [[Lackland Air Force Base]], Detachment 1 at [[Osan Air Base]], Korea, the [[1st Space Surveillance Squadron]] at [[Griffiss Air Force Base]], and the [[17th Space Surveillance Squadron]] at [[RAF Edzell]]. In 1995, the 1st Space Surveillance Squadron inactivated, and in 1996 the 17th Space Surveillance Squadron followed suit, with Detachment 1 inactivating in 1997. The remaining passive radar systems were shut down, with the 5th Space Surveillance Squadron inactivating in January 2002 and the 3rd Space Surveillance Squadron following in February 2002.<ref name=heritage/>
[[File:2008 Eglin AFB Site C-6 phased array building.jpg|thumb|[[AN/FPS-85]] radar at [[Eglin Air Force Base]].]]
The 21st Operations Group maintained a set of command and control squadrons to coordinate its primary missions. The [[1st Command and Control Squadron]], based at [[Cheyenne Mountain Air Force Station]], was responsible for tasking the [[United States Space Surveillance Network]] and maintained the [[space catalog]]. The [[2nd Command and Control Squadron]] operated out of [[Schriever Air Force Base]] and controlled the passive space surveillance network. The [[3rd Command and Control Squadron]] was based at [[Offutt Air Force Base]] and served as the alternate [[Missile Warning Center]]. In 1998, the 2nd Command and Control Squadron would transfer to the [[14th Air Force]] as passive space surveillance units began inactivating, while new capabilities at the [[Missile Warning Center]] rendered the 3rd Command and Control Squadron redundant, inactivating in 1999. The 1st Command and Control Squadron was realigned under the [[614th Air and Space Operations Center]] in June 2008. In 1996, the [[821st Space Group]] was activated at [[Buckley Air National Guard Base]] under the 21st Space Wing, gaining the [[Defense Support Program]] and its squadrons from the 21st Operations Group. On 1 October 1994, the 21st Crew Training Squadron inactivated and in 1997 the [[84th Airlift Flight]], which operated the [[Learjet C-21]] for [[Air Force Space Command]], was transferred to [[Air Mobility Command]].<ref name=heritage/>
{{Gallery | title = 21st Operations Group space control squadrons | align = center | width=120 | captionstyle = text-align:center; | File:4th Space Control Squadron.jpg|[[4th Space Control Squadron]] | File:16 Space Control Sq.jpg|[[16th Space Control Squadron]] | File:18th Space Control Squadron.jpg|[[18th Space Control Squadron]] | File:20th Space Control Squadron Emblem.jpg|[[20th Space Control Squadron]] | File:76th Space Control Squadron.png|[[76th Space Operations Squadron|76th Space Control Squadron]] (pre–2008) | File:76th Space Control Squadron new.PNG|[[76th Space Control Squadron]] (post–2008) }}
[[File:The night watchmen (3388920).jpeg|thumb|[[Ground-Based Electro-Optical Deep Space Surveillance]] (GEODSS) site at White Sands Missile Range.]]
Following increased proliferation of debris and international actors in space, the 21st Operations Group began to transition from space surveillance to space control, or counterspace, renaming its squadrons. Space control squadrons were intended to guard against hostile action while also preventing collision with space debris. The first space control squadron, the [[76th Space Operations Squadron]] was activated at Peterson Air Force Base in 2000 and renamed the 76th Space Control Squadron in January 2001, receiving initial operational capability on the Counter Communications System in September 2004. On 1 March 2003, all space surveillance squadrons were redesignated as space control squadrons. In July 2005, the [[4th Space Control Squadron]] at [[Holloman Air Force Base]] began to move into the space control mission in July 2005, activating its first counter communications system in April 2006, transferring to Peterson Air Force Base in July 2014 and absorbing the 76th Space Control Squadron in February 2015. In May 2007, the [[16th Space Control Squadron]] was activated at Peterson Air Force Base as a defensive space control squadron. As part of an Air Force manpower saving program, the [[18th Space Control Squadron]] was inactivated in April 2004, with its Detachments 1-4 directly realigned under the 21st Operations Group. In August 2004, the [[20th Space Control Squadron]] activated Detachment 1 at [[Naval Surface Warfare Center Dahlgren Division|Naval Support Activity Dahlgren]] to operate the [[Air Force Space Surveillance System]] (formerly the Navy Space Surveillance System) and the Alternate Space Control Center. Detachment 1, 20th Space Control Squadron was inactivated in April 2010, followed by the inactivation of Detachment 4, 21st Operations Group at [[Morón Air Base]] in March 2013. In April 2013, the [[13th Space Warning Squadron]] gained oversight of the [[Cobra Dane]] radar at [[Eareckson Air Station]], Alaska. On 20 April 2016, the GEODSS detachments transitioned from the 21st Operations Group to the 20th Space Control Squadron and the 18th Space Control Squadron was reactivated on 22 July 2016 at [[Vandenberg Air Force Base]].<ref name=heritage/>
In 2019, the 721st Operations Group was activated and gained the 4th Space Control Squadron and 16th Space Control Squadron.<ref>{{Cite web|url=https://www.spoc.spaceforce.mil/About-Us/Fact-Sheets/Display/Article/2334026/space-delta-3|title=Space Delta 3|website=Space Operations Command (SpOC)|access-date=25 March 2022|archive-date=12 April 2022|archive-url=https://web.archive.org/web/20220412190334/https://www.spoc.spaceforce.mil/About-Us/Fact-Sheets/Display/Article/2334026/space-delta-3|url-status=live}}</ref>
===The Space Force's space domain awareness delta=== {{Gallery | title = Mission Delta 2 squadrons | align = center | width=120 | captionstyle = text-align:center; | File:18th Space Defense Squadron emblem.png|[[18th Space Defense Squadron]] | File:20th Space Surveillance Squadron emblem.png|[[20th Space Surveillance Squadron]] | File:21st Operations Support Squadron emblem.png|[[21st Operations Support Squadron]] }}
Following the establishment of the [[United States Space Force]], the 21st Space Wing and 21st Operations Group remained units of the U.S. Air Force assigned to [[Space Operations Command|United States Space Force]]. On 24 July 2020, the Space Force reorganized its wings and groups into deltas, inactivating the 21st Space Wing and redesignated the 21st Operations Group as Space Delta 2. Space Delta 2 transferred its space warning squadrons to [[Space Delta 4]], retaining its space surveillance awareness and space defense squadrons. On 21 October 2020, with the redesignation of United States Space Force as Space Operations Command, Space Delta 2 transferred from a unit of the United States Air Force to the United States Space Force.<ref name=afhra /> On 31 October 2024 it was redesignated Mission Delta 2 and gained sustainment responsibilities, along with organic cyber defense and intelligence forces.<ref>{{Cite web | title=Two DELs transition to fully-integrated Mission Deltas > Space Operations Command (SpOC) > Article Display | url=https://www.spoc.spaceforce.mil/News/Article-Display/Article/3952582/two-dels-transition-to-fully-integrated-mission-deltas | archive-url=https://web.archive.org/web/20241106022819/https://www.spoc.spaceforce.mil/News/Article-Display/Article/3952582/two-dels-transition-to-fully-integrated-mission-deltas | access-date=2025-08-06 | archive-date=2024-11-06}}</ref>
==Symbolism== {{Gallery | title = Emblems of Mission Delta 2 and its predecessors | align = center | width=140 | captionstyle = text-align:center; |File:Emblem of Space Delta 2.png|Mission Delta 2 (2020–present) |File:21st Space Wing.png|21st Operations Group (1957–2019) |File:21st Fighter Group - World War II - Emblem.png|21st Fighter Group (1944–1946) |File:21 bombardment gp emblem (b&w) .jpg|21st Bombardment Group (1942–1943) }}
===21st Operations Group emblem=== The 21st Operations Group emblem was shared with the [[21st Space Wing]] and its other groups. The blue represents the vast blue sky-the 21st's area of operations. The upraised sword indicates the strength and readiness of the wing to perform its mission, whether in peace or war. The lightning is symbolic of the heavens beyond, the stormy power and protective Lord. The Air Force blue, red, and yellow signifies the three fighter squadrons of the 21st Fighter–Bomber Wing. The emblem was approved on 23 July 1957.<ref name=heritage/>
The motto "Strength and Preparedness" is derived from the original motto of the 21st Fighter-bomber Wing "Fortitudo et Preparatio."<ref name=heritage/>
== Structure == {|class="wikitable" |- !Emblem !Name !Function !Headquarters !Space domain awareness systems !Detachments |- !colspan=6| Squadrons |- | [[File:15th Space Surveillance Squadron emblem.png|70px]] || [[15th Space Surveillance Squadron]]<ref name="feature"/> || [[Research and development]] || [[Maui]], [[Hawaii]] || || |- | [[File:18th Space Defense Squadron emblem.png|70px]] || [[18th Space Defense Squadron]] || [[Space domain awareness]] ||[[Vandenberg Space Force Base]], California ||[[Space Defense Operations Center]]<ref>{{Cite web|url=https://www.peterson.spaceforce.mil/About/Fact-Sheets/Display/Article/2356622/18th-space-control-squadron/|title=18th Space Control Squadron|website=Peterson Air Force Base|access-date=December 15, 2020|archive-date=May 5, 2021|archive-url=https://web.archive.org/web/20210505034340/https://www.peterson.spaceforce.mil/About/Fact-Sheets/Display/Article/2356622/18th-space-control-squadron/|url-status=live}} {{PD-notice}}</ref><br />[[Satellite Catalog Number|Space Catalog]]|| |- | [[File:19th Space Defense Squadron emblem.png|70px]] || [[19th Space Defense Squadron]]<ref>{{cite web | url=https://www.spacecom.mil/MEDIA/IMAGERY/igphoto/2002978691/ | title=18 SPCS re-designates to 18th Space Defense Squadron | access-date=19 April 2022 | archive-date=4 June 2022 | archive-url=https://web.archive.org/web/20220604092709/https://www.spacecom.mil/MEDIA/IMAGERY/igphoto/2002978691/ | url-status=live }}</ref> || [[Space domain awareness]] for government, civilian, and international users || [[Naval Support Facility Dahlgren]], Virginia || || |- | [[File:20th Space Surveillance Squadron emblem.png|70px]] || [[20th Space Surveillance Squadron]] || [[Space domain awareness]] ||[[Eglin Air Force Base]], Florida || [[Eglin AFB Site C-6|AN/FPS-85]] [[phased array|phased array radar]]<ref>{{Cite web|url=https://www.eglin.af.mil/About-Us/Fact-Sheets/Display/Article/390961/20th-space-surveillance-squadron/|title=20th Space Control Squadron|website=Eglin Air Force Base|access-date=December 15, 2020|archive-date=January 19, 2021|archive-url=https://web.archive.org/web/20210119152719/https://www.eglin.af.mil/About-Us/Fact-Sheets/Display/Article/390961/20th-space-control-squadron/|url-status=live}} {{PD-notice}}</ref><br />[[Ground-based Electro-Optical Deep Space Surveillance]] (Detachments 1, 2, 3)<br />[[Space Fence]] (Det 4) ||Detachment 1: [[White Sands Missile Range]], New Mexico<br />Detachment 2: [[Naval Support Facility Diego Garcia]], British Indian Ocean Territory<Br/>Detachment 4: [[Air Force Maui Optical and Supercomputing observatory|Maui Space Surveillance Complex]], Hawaii<br />Detachment 4: [[Redstone Arsenal]], Alabama, and [[Ronald Reagan Ballistic Missile Defense Test Site]], Marshall Islands |- | [[File:USSF 2 SUSTAINMENT SQUADRON.png|frameless|93x93px]]|| [[2nd Sustainment Squadron]] || Sustainment || [[Peterson Space Force Base]], Colorado|| || |- !colspan=6| Detachments |- | || Detachment 1 || [[Weather reconnaissance]] || [[Suitland, Maryland]]<ref name="video"/> || || |- | [[File:Space Delta 2, Detachment 2 emblem.png|70px]] || Detachment 2 || [[Space domain awareness]] || [[Kirtland Air Force Base]], New Mexico<ref name="video"/> || || |- |}
== List of commanders == {| class="wikitable sortable" style="text-align:center;" |- ! rowspan=2| {{abbr|No.|Number}} ! colspan=2| Commander ! colspan=3| Term ! rowspan=2| {{abbr|Ref|Reference(s)}} |- ! Portrait ! Name ! Took office ! Left office ! Duration |- {{Officeholder table | order = 1 | military_rank = Colonel | image = Col Matthew S. Cantore (2).jpg | officeholder = [[Matthew Cantore]] | officeholder_sort = Cantore, Matthew S. | born_year = | died_year = | term_start = 24 July 2020 | term_end = 14 June 2021 | timeinoffice = {{ayd|24 July 2020|14 June 2021}} | alt_officeholder = <ref>{{Cite web|url=https://www.peterson.spaceforce.mil/About/Biographies/Display/Article/1838328/colonel-matthew-s-cantore/|title=COLONEL MATTHEW S. CANTORE|website=www.peterson.spaceforce.mil|access-date=June 15, 2021|archive-date=November 16, 2020|archive-url=https://web.archive.org/web/20201116110724/https://www.peterson.spaceforce.mil/About/Biographies/Display/Article/1838328/colonel-matthew-s-cantore/|url-status=dead}}{{PD-notice}}</ref> }} {{Officeholder table | order = 2 | military_rank = Colonel | image = Col Marc A. Brock.jpg | officeholder = Marc A. Brock | officeholder_sort = Brock, Marc A. | born_year = | died_year = | term_start = 14 June 2021 | term_end = 23 June 2023 | timeinoffice = {{ayd|14 June 2021|23 June 2023}} | alt_officeholder = <ref>{{Cite web|url=https://www.peterson.spaceforce.mil/About-Us/Biographies/Display/Article/2658572/colonel-marc-a-brock/|title=COLONEL MARC A. BROCK|website=www.peterson.spaceforce.mil|access-date=10 December 2021|archive-date=29 October 2021|archive-url=https://web.archive.org/web/20211029030348/https://www.peterson.spaceforce.mil/About-Us/Biographies/Display/Article/2658572/colonel-marc-a-brock/|url-status=live}}{{PD-notice}}</ref><ref name="turnover">{{Cite web|url=https://www.peterson.spaceforce.mil/News/Article/2657666/space-delta-2-changes-command/|title=Space Delta 2 changes command|website=Peterson Air Force Base|access-date=15 June 2021|archive-date=1 August 2021|archive-url=https://web.archive.org/web/20210801101101/https://www.peterson.spaceforce.mil/News/Article/2657666/space-delta-2-changes-command/|url-status=live}} {{PD-notice}}</ref> }} {{Officeholder table | order = 2 | military_rank = Colonel | image = Col Raj Agrawal (2).jpg | officeholder = Raj Agrawal | officeholder_sort = Agrawal, Raj | born_year = | died_year = | term_start = 23 June 2023 | term_end = 3 July 2025 | timeinoffice = {{ayd|23 June 2023|3 July 2025}} | alt_officeholder = <ref>{{Cite web|url=https://www.spoc.spaceforce.mil/News/Article-Display/Article/3439301/|title=Col. Raj Agrawal assumes command of Delta 2|date=23 June 2023|website=Space Operations Command (SpOC)|access-date=15 February 2024|archive-date=15 February 2024|archive-url=https://web.archive.org/web/20240215054756/https://www.spoc.spaceforce.mil/News/Article-Display/Article/3439301|url-status=live}}</ref><ref>{{Cite web|url=https://www.petersonschriever.spaceforce.mil/About-Us/Biographies/Display/Article/3440587/raj-agrawal/|title=RAJ AGRAWAL|website=Peterson and Schriever Space Force Base|access-date=15 February 2024|archive-date=15 February 2024|archive-url=https://web.archive.org/web/20240215054753/https://www.petersonschriever.spaceforce.mil/About-Us/Biographies/Display/Article/3440587/raj-agrawal/|url-status=live}}</ref> }} {{Officeholder table | order = 3 | military_rank = Colonel | image = Lt Col Barry A. Croker.jpg | officeholder = Barry A. Croker | officeholder_sort = Croker, Barry A. | born_year = | died_year = | term_start = 3 July 2025 | timeinoffice = {{ayd|3 July 2025}} | alt_officeholder = <ref>{{cite web | title=Mission Delta 2 Conducts Change of Command | work=Space Operations Command (SpOC) | url=https://www.spoc.spaceforce.mil/News/Article-Display/Article/4236693/mission-delta-2-conducts-change-of-command }}</ref> }} |}
==See also== *[[No. 1 Space Surveillance Unit]]
== References == {{Commons category}} {{Reflist}}
{{United States Space Force}}
[[Category:Deltas of the United States Space Force]] [[Category:Military units and formations established in 1942]] [[Category:Military units and formations established in 2020]]