The Space Development Agency (SDA) is a United States Space Force direct-reporting unit tasked with deploying disruptive space technology.SDA.mil About Us One of the technologies being worked on is space-based missile tracking using large global satellite constellations made up of industry-procured low-cost satellites.Brian Everstine (22 Sep 2022) Why Space Force Wants Out Of GEO, Long Development Cycles noMoreGeoSats. For the Space Force, last of the geosynchronous satellites. Gone by 2040 The SDA has been managed by the United States Space Force since October 2022.United States Space Force By February 2024 the SDA had 38 satellites on orbit.Audrey Decker (30 Aug 2023) SDA readies second batch of satellites for its space data network A test of Link-16 Theresa Hitchens (5 Sep 2023) SDA launches 13 more Tranche 0 data relay, missile tracking sats for 'warfighter immersion' SpaceX (2 Sep 2023) Space Development Agency's Second Tranche 0 Mission SDA intends to have at least 1,000 satellites in low Earth orbit by 2026.
The Space Development Agency's network of military satellites is called the Proliferated Warfighter Space Architecture. It is highlighted by White House executive order as a key element of the future Golden Dome (missile defense system).
History The Space Development Agency (SDA) was established in 2019 by Mike Griffin with his appointment to Under Secretary of Defense (R&E) by President Donald Trump. Griffin was a long time advocate for low Earth orbit constellations to eliminate U.S. vulnerability to ballistic missiles with his work on space-based interceptors for the Strategic Defense Initiative and Brilliant Pebbles in the 1980s. These programs, however, were discontinued in the 1990s due to high cost and political disagreement. Later, the United States and other countries developed hypersonic weapons, which Griffin argued were thermally dimmer and could only be reliably tracked by low-flying satellites with infrared sensors, creating a need to resurrect such programs. In addition to hypersonic weapons, the memorandum establishing the SDA also calls for a new space architecture "not bound by legacy methods or culture" that provides unifying command and control through a cross-domain artificial intelligence-enabled network.Secretary of Defense
The SDA originally introduced the National Defense Space Architecture,(2022) National Defense Space Architecture (NDSA) Systems, Technologies, and Emerging Capabilities (STEC) About UsNathan Strout (1 Jul 2021) The Space Development Agency now has demo satellites on orbit. Here's what they'll do. Transporter-2: Mandrake 2, the Laser Interconnect and Networking Communications System (LINCS), and the Prototype On-orbit Experimental Testbed (POET). Yam-3 for data fusion. Pitboss for Autonomous mission management. which was later renamed the Proliferated Warfighter Space Architecture. It advances a network of global orbiters organized into layers, each supporting distinct military functions such as communications, surveillance, navigation, battle management, deterrence, and missile defense. The satellite constellation is to be interconnected by free-space optical laser terminalsSandra Erwin (28 Sep 2023) Mynaric optical terminals selected for Northrop Grumman satellites pass key tests T1TL interop with CACI in a secure command and control optical mesh network. Satellites are to be low cost and "proliferated" in low Earth orbit. New commercial technology such as reusable launch systems have reduced deployment costs and new mass-produced commercial satellites offer less "juicy" targets for anti-satellite weapons by being inexpensive and potentially hard to distinguish from other commercial satellites. Development follows a spiral model, with each generation informed by lessons from earlier deployments, and new satellites launched regularly to replace those with relatively short operational lifespans. The SDA expects to field and maintain a constellation of at least 1,000 satellites on orbit by 2026.
The SDA has mostly avoided flaws that plagued earlier proliferated missile defense programs such as Brilliant Pebbles. The Anti-Ballistic Missile Treaty was a major impediment in the past, as these systems were deemed non-compliant with the treaty by Congress. However, George W. Bush withdrew the United States from the treaty in 2002, eliminating this barrier. Over the years, launch and manufacturing costs have been greatly reduced. Decades after the SDIO's DC-X failed there are now commercial reusable launch vehicles such as SpaceX's Falcon 9 rocket. Meanwhile mass manufacturing as with Starlink has proven the potential for lower satellite build costs.
Political and administrative opposition to SDA came from 24th secretary of the Air Force Heather Wilson who argued that "launching hundreds of cheap satellites into theater as a substitute for the complex architectures where we provide key capabilities to the warfighter will result in failure on America's worst day if relied upon alone." Members of Congress also gave concerns that SDA would drain resources and jobs from Air Force and questioned why DoD had to create a separate organization to circumvent its own procurement process. Despite the pushback, the Pentagon did not require congressional authorization to create the SDA, and Wilson was overruled by Patrick M. Shanahan, who became acting defense secretary by appointment of Donald Trump. He placed the new agency under the authority and control of Mike Griffin who was also appointed as Under Secretary of Defense (R&E).
Despite these early successes, SDA still faces critical challenges. The Union of Concerned Scientists warned SDA could escalate tensions with Russia and China and called the project "fundamentally destabilizing". Both China and Russia brought concerns to the United Nations about the U.S. plans for militarization of space. The Carnegie Endowment for International Peace has advocated for better use of arms control and international agreements such as a treaty halting related development by all parties to prevent an arms race in space.
Critics have reiterated longstanding concerns that ground-based lasers can easily "paint" satellites in low Earth orbit, temporarily blinding their sensors. The APS reporting the energy needed for this is very low. Likewise, RF jamming is simpler when communication and radar satellites are in lower altitudes as less power is needed to saturate their low-noise amplifiers. It is also far easier to launch an anti-satellite weapon to destroy satellites in low Earth orbit (as demonstrated with small ASM-135 or RIM-161 missiles) given much less energy is required to kinetically intersect than to enter and maintain orbit. An adversary would simply need to "punch a hole" in the constellation immediately before launching an attack.Sandra Erwin (21 Dec 2017) New report slams idea of a missile defense shield in space by Thomas Roberts, CSIS When the Biden administration took ownership of the program in 2021, they appeared to take heed of these concerns but still signed on to a $500M increase for the agency in the FY2023 spending bill.
The Heritage Foundation, a conservative think tank, dubbed the Space Development Agency "a model for the military". In their 2025 Mandate for Leadership, they call to develop new offensive space capabilities to "impose [American] will if necessary". They further claim the Biden administration "has eliminated almost all offensive deterrence capabilities" in space that were planned under the Trump administration.
In 2020, 13th Assistant Secretary of the Air Force for Acquisition, Technology and Logistics Will Roper expressed interest in the SpaceX Starlink satellite internet constellation as a platform for the SDA.Same Skove (13 Sep 2023) Navies face 'dreadnought' moment as Ukraine destroys more Russian warships, British admiral says ' "We're once again facing something completely new, a paradigm shift", the First Sea Lord said'. Starlink satellites can be jammed.
SDA awarded its first contracts in August 2020. Lockheed Martin received $188 million and York Space Systems received $94 million to each build 10 data relay satellites for its transport layer. In October 2020, SDA chose SpaceX and L3Harris Technologies to develop four satellites each to detect and track ballistic and hypersonic missiles. The initial tranche of satellites were originally scheduled to launch September 2022. However, the initial launch slipped due to supply-chain issues for microelectronics such as radios, software problems, and protests by Raytheon and Airbus over procurement and evaluation process. SDA industry partners now include SpaceX, L3Harris Technologies, Northrop Grumman, Ball Aerospace and General Dynamics.
A number of experimental satellites were launched in 2021. SDA plans to test some of the key technologies in a series of on-orbit experiments that went up on Transporter-2: Mandrake 2, the Laser Interconnect and Networking Communications System (LINCS), and the Prototype On-orbit Experimental Testbed (POET).
SDA's current schedule expects Tranche 0 capability will be on orbit in time to support a summer 2023 demonstration.Theresa Hitchens (29 Mar 2023) Space Development Agency readies launch of first satellites for comms, missile tracking Courtney Albon (28 Apr 2023) How three space agencies are collaborating on next-gen missile warning Link 16 connectivity between Five Eyes nations, via Low Earth Orbit Tranche 0 satellites was demonstrated from 21 November to 27 November 2023.Courtney Albon (28 Nov 2023) Space Development Agency demonstrates Link 16 satellite connectivity Theresa Hitchens (28 Nov 2923) SDA demos first-ever space-to-ground Link 16 connection Global coverage of missile launches will take 40 downward-looking satellites.Courtney Albon (12 Apr 2024) Space Development Agency satellites poised to track first missile test By year-end 2025 there will be 126 Link-16 satellites in orbit for intercommunication, using Tranche 1 Tracking capabilities.Theresa Hitchens (18 Mar 2024) SDA's data relay, missile tracking networks to be operational by end of 2025: Tournear Tranche 2 Tracking capability will start in 2026.
Tranche 1 satellites were solicited for bid in 2021,Theresa Hitchens (27 Aug 2021) SDA Opens Contest For First Operational Constellation 30 Aug 2021 RFP for Tranche 1 Transport Layer (T1TL) Jan 2022 expecting first launch in September 2024, and monthly launches thereafter.Greg Hadley (5 Apr 2023) SDA's Tournear 'Just Not' Afraid of Satellite Shootdowns. Supply Chain Is the Greater Worry. : Tranche 1 detail; T1 DES (Demonstration and Experimentation System) detail; Tranche 2 detail;Courtney Albon (10 Apr 2023) US Space Force to simplify timelines, purchases as launches surge National Security Space Launch (NSSL Phase 3) FY25 to FY34 Tranche 1 totals more than 150 satellites: 126 in Tranche 1 Transport Layer; 35 in Tranche 1 Tracking Layer; 12 in the Tranche 1 Demonstration and Experimentation System. In 2022 contracts were awarded to York Space Systems, Lockheed Martin Space, and Northrop Grumman Space Systems.