Space Delta 2 - Space Domain Awareness and Space Battle Management

 Space Delta 2 (DEL 2) conducts Space Domain Awareness and Space Battle Management operations to identify, characterize, and exploit opportunities and mitigate vulnerabilities in the national security space terrain on behalf of the United States Space Force and United States Space Command.

Space Delta 2 is headquartered at Peterson Space Force Base, Colorado and is one of the most geographically dispersed deltas in the U.S. Space Force, having a presence at:

  • Schriever Space Force Base, Colorado
  • Vandenberg Space Force Base, California
  • Maui Space Surveillance Complex, Hawaii 
  • Eglin Air Force Base, Florida 
  • Kirtland Air Force Base, New Mexico 
  • Naval Support Facility Dahlgren, Virginia
  • Naval Support Facility Diego Garcia, British Indian Ocean Territory
  • U.S. Army Garrison Kwajalein Atoll, Republic of the Marshall Islands
  • Stallion Army Airfield, New Mexico
  • National Oceanic and Atmospheric Administration Satellite Operations Facility in Suitland, Maryland
  • RAAF Base Edinburgh, Australia 

Please visit to view the Space Force’s current orbital catalog. Space Delta 2 tracks 44,700 space objectives, including 8,900 active payloads, 16,600 analyst objects, and 19,200 pieces of orbital debris.


Generate, present, sustain, and improve combat space domain awareness forces who identify, characterize, and exploit opportunities to secure our Nation’s interests in, from, and to space.


Tactical space battle managers who turn understanding into opportunity.

Space Domain Awareness encompasses the effective identification, characterization and understanding of any factor associated with the space domain that could affect space operations and thereby impact the security, safety, economy, or environment of our Nation. Space situational awareness (SSA) is a subset of SDA, providing situational awareness and object intelligence in the physical domain of space. DEL 2 space surveillance squadrons generate SSA data, which is then fused with other U.S. Space Force, joint, and multinational sensors, along with commercially acquired data, by DEL 2’s space defense squadrons to form a common understanding of the national security space terrain. This compiled data, known as the space catalog, is distributed across the military, intelligence community, commercial space entities, and to the public, free of charge.

The SDA mission also extends to environmental monitoring, which includes sensing, characterizing, and exploiting the natural environment. DEL 2 partners with NOAA to operate the Space Force’s space-based environmental monitoring spacecraft. Space environmental monitoring provides critical warning of natural environmental threats in space, ensuring the safety of US, allied, and commercial spacecraft. Terrestrial environmental monitoring provides information and support to joint forces, including terrestrial-based space forces, throughout the world with metrological and oceanographic information affecting all domains.

Space Battle Management is the knowledge of how to orient the space domain and skill in making decisions to preserve mission, deny adversary access, and ultimately ensure mission accomplishment. It includes the ability to identify hostile actions and entities, conduct combat identification, target, and direct action in response to an evolving threat environment. Space Battle Management is how DEL 2 operationalizes SDA to produce warfighting effects, collaborating closely with Space Delta 15 to close the kill chain and ensure space superiority.


Lineage and honors

Space Delta 2 is one of the oldest deltas in the United States Space Force, tracing its history back to World War II. Established on January 13, 1942, as the 21st Bombardment Group, the group was activated on February 1 as an operational training unit, flying the A-20 Havoc, B-18 Bolo, B-25 Mitchell, and B-26 Marauder. The 21st Bombardment Group flew antisubmarine patrols against German U-Boats in the Caribbean Sea, before being disestablished on October 10, 1943.

It was reestablished as the 21st Fighter Group on March 31, 1944, flying the P-39Q Airacobra, P-38 Lightning, and P-51 Mustang in air defense missions over the Hawaiian Islands. In February 1945, the 21st Fighter Group deployed for the Invasion of Iwo Jima, flying close air support for Marines across the island. On the morning of March 26, the 21st Fighter Group’s basecamp was attacked by Japanese soldiers. Assisted by a patrol of Marines, the 21st repulsed the attack in vicious tent-to-tent fighting. Ultimately, 250 enemy soldiers were killed, while 14 Airmen were killed and 50 were wounded, including the group commander, Colonel Kenneth Powell. Colonel Powell would later be promoted to Major General and serve in the Air Force space program as the 1st Strategic Aerospace Division’s deputy commander at Vandenberg Air Force Base, California.

After helping the Marines win control of Iwo Jima, the 21st Fighter Group began flying long-range bomber escort missions over the Japanese home islands. On April 7, 1945, the 21st Fighter Group escorted a formation of B-29 Superfortress bombers over the heavily defended Nakajima aircraft factory in Tokyo, downing eight Japanese aircraft. This mission marked the first time that fighters had escorted bombers over the Japanese home islands, earning the 21st Fighter Group the highest possible unit award – the Distinguished (now Presidential) Unit Citation. On April 19, 1945, fighters from the 21st conducted the first strafing missions over Japan and attacked enemy airfields where Kamikaze attacks originated from. The 21st Fighter Group flew its last combat mission on August 14, 1945, and briefly flew the P-47 Thunderbolt before inactivating on October 10, 1946.

On January 1, 1943, the 21st Fighter-Bomber Group was reestablished at George Air Force Base in California, flying air defense missions in the F-51 Mustang before converting to the F-86F Sabre. On June 22, 1954, the Secretary of the Air Force directed the 21st Fighter-Group to relocate to Chambley Air Base in France to serve as a key element of NATO’s air forces. The group briefly added T-33 Shooting Star trainer jets to its hangers in 1957, before being inactivated on February 8, 1958.

It was briefly reactivated as the 21st Operations Group from September 26 to December 19, 1991, as part of NORAD’s Alaskan Air Defense forces, flying alert missions with F-15C/D Eagles against Soviet bombers and preparing to conduct counterland missions in F-15E Strike Eagles.

In 1991, DEL 2 made the transition from air to space, activating at Peterson Air Force Base under Air Force Space Command and assuming responsibility for the 1st Space Wing’s space surveillance and missile warning units. In 1995, the 73d Space Group (today Space Delta 3) inactivated and its space control mission and squadrons transferred to the 21st Operations Group. In 2004, the 21st Operations Group transferred its space-based overhead persistent infrared mission, including Defense Support Program spacecraft, to what would become Space Delta 4. At its height, the 21st Operations Group was the largest in the entire Air Force. In 2019, the 21st Operations Group’s electromagnetic warfare capabilities were separated into the 721st Operations Group, and later Space Delta 3.

On July 24, 2020, the 21st Operations Group was redesignated as Space Delta 2 on July 24, 2020 and formally transferred from the U.S. Air Force to the U.S. Space Force with redesignation of United States Space Force as Space Operations Command on October 21, 2020. As part of the transition from Air Force group to Space Force delta, DEL 2 reoriented around Space Domain Awareness and Space Battle Management, transferring its ground-based missile warning radars to Space Delta 4 and gaining Space-Based Environmental Monitoring from the 50th Operations Group (now Space Delta 8).


Description. On a black delta flight symbol shape, issuing from the bottom left corner a partial dark gray sphere, grid-lined black, surmounted above by the Arabic numeral “2” in dark blue outlined in gray and interlaced by a silver contrail emanating from the bottom left corner terminating at a red delta outlined in silver; at bottom center a diagonal red lightning bolt accented silver featuring a silver contrail emerging from behind the sphere; all within a narrow gray border.

Significance. The midnight blue and steel outlined number “2” represents all the personnel that protect and defend the United States and its allies from attack in, through and from space. The globe represents the physical home of the Space Delta 2 as the “Foundation of Space Superiority.” The lightning bolt emitting from the globe symbolizes the performance and vigilance of Delta 2’s sensors. The delta rocketing through the number “2” represents the unit’s continued maintenance and tracking of the satellite catalog and supports space operators around the globe. The steel border represents the foundation and structure the Field Command provides to Space Delta 2.


15th Space Surveillance Squadron: 15 SPSS, located at the Maui Space Surveillance Complex (MSSC), Hawaii, develops, assesses, delivers, and operates cutting-edge SDA capabilities to support warfighter needs. The 15 SPSS has two missions: SDA operations and SDA research and development. It consists of a blended organizational structure of Space Force and Air Force Research Laboratory personnel. 15 SPSS operates three AN/FSD-3 Ground-Based Electro-Optical Deep Space Surveillance (GEODSS) systems at the Maui Space Surveillance Complex, while Detachment 1 operates at Stallion Army Airfield in Socorro, New Mexico and Detachment 2 operates at NSF Diego Garcia. The squadron also provides oversight of the Maui High Performance Computer Center Vanguard Center.

18th Space Defense Squadron: 18 SDS, located at Vandenberg SFB, California, drives space combat operations through SDA mission management, custody operations, spaceflight safety, and analysis through integrating sensors (United States Government, multinational partner, and commercial) in order to deliver a combat-ready common operational picture to support senior leader decisions. 18 SDS is the lead battle management squadron for mapping the geocentric space terrain. 18 SDS, Detachment 1, located at Schriever SFB, and integrates with Space Delta 15 to provides combat focused understanding of on-orbit adversary threats within operationally relevant timelines in support of space superiority operations.

19th Space Defense Squadron: 19 SDS, located at NSF Dahlgren, Virginia, innovates and federates space domain awareness operations to maintain freedom of action for U.S., allied, and commercial partners.  19 SDS is the lead battle management squadron for mapping the cislunar regime and the only Space Force unit with a dedicated Navy fleet support mission. 19 SDS Operating Location Alpha also provides oversight to the Space Force’s Defense Meteorological Support Program (DMSP) and the Electro-optical/Infrared Weather System – Geosynchronous (EWS-G) through a detachment at the NOAA Satellite Operations Facility in Suitland, MD.

20th Space Surveillance Squadron: 20 SPSS, located at Eglin Air Force Base (AFB) Site C-6, Florida, executes multiplatform, tactical space domain characterization and responsiveness to achieve DEL 2 and USSPACECOM warfighting intent. 20 SPSS operates the AN/FPS-85 Phased Array Deep Space Radar at Eglin AFB Site C-6 and the AN/FSY-3 Space Fence Radar, located at U.S. Army Garrison Kwajalein Atoll,  Republic of the Marshall Islands, from the Integrated Radar Operations Center (IROC). 20 SPSS future missions include the Deep Space Advanced Radar Capability (DARC).

Detachment 2: DEL 2, Det 2, located at the Starfire Optical Range at Kirtland AFB, New Mexico, maintains space superiority for USSF and its allies by incorporating developmental, advanced ground based optical sensor capabilities to the operational optical community.

Operating Location Bravo: DEL 2, OL-B is to serve as the DEL 2 Liaison Officer to the Australian Defence Space Command No. 1 Space Surveillance Unit. Located at RAAF Base Edinburgh, South Australia, 1 SSU remotely operates the U.S. AN/FPQ-15 C-Band Space Surveillance Radar and Space Surveillance Telescope at Naval Communications Station Harold E. Holt, Western Australia.

(Current as of December 2023)