TheSpace Development Agency (SDA) is aUnited States Space Forcedirect-reporting unit tasked with deploying disruptive space technology.[1] One of the technologies being worked on is space-basedmissile tracking using large globalsatellite constellations made up of industry-procured low-cost satellites.[2][3][4] The SDA has been managed by the United States Space Force since October 2022.[5] By February 2024 the SDA had 38 satellites on orbit.[6] SDA intends to have at least 1,000 satellites inlow Earth orbit by 2026.[7]
The Space Development Agency's network of military satellites is called the Proliferated Warfighter Space Architecture.[8] It is highlighted byWhite House executive order as a key element of the futureGolden Dome (missile defense system).[9][10]
The Space Development Agency (SDA) was established in 2019 byMike Griffin with his appointment toUnder Secretary of Defense (R&E) byPresident Donald Trump.[11] Griffin was a long time advocate forlow Earth orbit constellations to eliminate U.S. vulnerability toballistic missiles with his work onspace-based interceptors for theStrategic Defense Initiative andBrilliant Pebbles in the 1980s. These programs, however, were discontinued in the 1990s due to high cost and political disagreement.[12] Later, the United States and other countries developedhypersonic 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.[13][2] 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 unifyingcommand and control through a cross-domainartificial intelligence-enabled network.[14]
The Space Development Agency (SDA) originally introduced theNational Defense Space Architecture,,[15][16][17] which was later renamed theProliferated Warfighter Space Architecture.[a] 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. Thesatellite constellation is to be interconnected byfree-space optical laser terminals[18] in a secure command and controloptical mesh network.[19] Satellites are to be low cost and "proliferated" in low Earth orbit. New commercial technology such asreusable launch systems have reduced deployment costs[20] and new mass-produced commercial satellites offer less "juicy" targets foranti-satellite weapons by being inexpensive and potentially hard to distinguish from other commercial satellites.[2] Development follows aspiral model,[b][c] 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.[7]
The SDA has mostly avoided flaws that plagued earlier proliferated missile defense programs such asBrilliant Pebbles. TheAnti-Ballistic Missile Treaty was a major impediment in the past, as these systems were deemed non-compliant with the treaty by Congress.[12] However,George W. Bush withdrew the United States from the treaty in 2002, eliminating this barrier.[21] Over the years, launch and manufacturing costs have been greatly reduced. Decades after theSDIO’sDC-X failed there are now commercialreusable launch vehicles such asSpaceX'sFalcon 9 rocket.[22] Meanwhilemass manufacturing as withStarlink has proven the potential for lower satellite build costs.[20]
Political and administrative opposition to SDA came from 24th Secretary of the Air ForceHeather 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."[7] 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 byPatrick M. Shanahan, who became acting defense secretary by appointment ofDonald Trump. He placed the new agency under the authority and control ofMike Griffin who was also appointed asUnder Secretary of Defense (R&E).[11]
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.[26] Likewise,RF jamming is simpler when communication and radar satellites are in lower altitudes as less power is needed to saturate theirlow-noise amplifiers. It is also far easier to launch ananti-satellite weapon to destroy satellites in low Earth orbit (as demonstrated with smallASM-135 orRIM-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.[27][23][28] When theBiden administration took ownership of the program in 2021, they appeared to take heed of these concerns[29] but still signed on to a $500M increase for the agency in the FY2023 spending bill.[30]
The Heritage Foundation, a conservative think tank, dubbed the Space Development Agency "a model for the military". In their2025 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.[31]
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 choseSpaceX andL3Harris Technologies to develop four satellites each to detect and track ballistic and hypersonic missiles.[34] The initial tranche of satellites were originally scheduled to launch September 2022.[19] However, the initial launch slipped due to supply-chain issues for microelectronics such as radios,[35] software problems, and protests byRaytheon andAirbus over procurement and evaluation process.[36] SDA industry partners now includeSpaceX,L3Harris Technologies,Northrop Grumman,Ball Aerospace andGeneral Dynamics.[7]
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 onTransporter-2: Mandrake 2, the Laser Interconnect and Networking Communications System (LINCS), and the Prototype On-orbit Experimental Testbed (POET).[37]
SDA's current schedule expects Tranche 0 capability[c][d] will be on orbit in time to support a summer 2023 demonstration.[36][38][39][40]Link 16 connectivity betweenFive Eyes nations, via Low Earth Orbit Tranche 0 satellites was demonstrated from 21 November to 27 November 2023.[41][42] Global coverage of missile launches will take 40 downward-looking satellites.[43] By year-end 2025 there will be 126 Link-16 satellites in orbit for intercommunication, using Tranche 1 Tracking capabilities.[44] Tranche 2 Tracking capability will start in 2026.[44]
Tranche 1 satellites were solicited for bid in 2021,[45] expecting first launch in September 2024,[46] and monthly launches thereafter.[47][48] 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.[47] In 2022 contracts were awarded to York Space Systems, Lockheed Martin Space, and Northrop Grumman Space Systems.[49]
Tranche 2 satellites were solicited for bid in 2023,[50] for launch in 2026.[50] This consists of more than 550 satellites: 250 in the Transport Layer; 50 in the Tracking Layer; Transport Layer will have 100 Alpha satellites, 72 Beta satellites, and 44 Gamma satellites;[47] The Beta satellitesRequest for Proposal (RFP) was released in the 2nd week of April.[47] The Alpha RFP was released in June 2023 and Gamma is scheduled for early 2024.[47] The Alpha satellites are similar to those in the Tranche 1 Transport Layer; the Beta satellites will have UHF and tactical communications payloads; the Gamma satellites will carry advanced waveform payloads.[47][51] York Space Systems will build 62 satellites for the Tranche 2 Transport Layer.[52] In 2023 contracts for 72 satellites were awarded to Northrop Grumman and Lockheed Martin (for 36 Beta satellites apiece).[53][54][55][56] In 2024 a third vendor, Rocket Lab LLC, was selected to supply 18 space vehicles, an additional part of the Beta Tranche 2 Tracking Layer (T2TL) tranche, for a total of 90 space vehicles in the Beta T2TL tranche.[57]
On 16 January 2024, the SDA announced an award to three vendors worth up to $2.5 billion. These vendors will supply "preliminary fire control" satellites in the Tranche 2 Tracking Layer. They will carry infrared (IR)cameras, with a mix offields of view (FOVs).[58][59] The FOVs in the IR cameras will be either wide FOV (WFOV), or medium FOV (MFOV) for low-resolution, or higher-resolution tracking capability respectively.[58] If such a satellite were to prove performant, and launched early, and no later than April 2027, a vendor could receive an incentive payment.[58] Each vendor is to provide 18 satellites, of which 16 are to carry WFOV cameras; the remaining two are to be MFOV cameras.[d][59][58] The Proliferated Warfighter Space Architecture (PWSA) will rely on these preliminary fire control satellites to perform theJADC2 concept.[58][60] Tranche 2 Tracking capability will start after the 2026 launches.[44]
This section mayrequirecleanup to meet Wikipedia'squality standards. The specific problem is:Article has run-on paragraphs and has anchors that are used elsewhere on Wikipedia but link into the middle of the text that should be their own sections or redirects. Relevant discussion may be found on thetalk page. Please helpimprove this section if you can.(May 2024) (Learn how and when to remove this message)
SDA satellites are the first to have direct-to-weapon control, as noted by SDA's technical director, Frank Turner. This capability allows for a seamless connection between the satellite data and weapon systems. The Beta satellites will attempt “extremely difficult” contacts with aircraft and missiles in flight, Turner said.[66]
Thesatellite constellations are innear-polarlow Earth orbit.[82] Hundreds of satellites are expected by the end of the 2020s.[17] "Would you be able to take out some of these satellites? Probably. Would you be able to take outall of these satellites? Probably not, before you are going to have a really bad day."—Derek Tournear[83]: min -2:10 before the end of the video clip [84][74]
NExT (National Defense Space Architecture (NDSA)[a] Experimental Testbed)[c] is a test bed of 10 space vehicles and associated mission-enabling ground systems, for realizing its various aspects, in miniature, before its larger, later scheduled deployments. In particular, the capability to retain and/or relay messages forcommand and control (C2) can then be demonstrated on the NExT test bed, before deployment at scale.[85][86]
Using the satellites of Tranche 0, the SDA will be demonstrating the new capabilities[c] of the PWSA[a] to the warfighters, to aid in concept development (using the "warfighter immersion tranche").[87][63][46]
User equipment (Earth stations and weapon systems)[83][92] SDA has selected the "ground Operations and Integration (O&I) segment for Tranche 1".[93] The Advanced Fire Control Ground Infrastructure (AFCGI) program includes data from LEO satellites.[60]
Transport layer intersatellite data[82] Tranche 1 Transport Layer (T1TL):[61] T1TL forms amesh network in a constellation of small satellites in Low earth orbit (LEO). Each satellite would have 4 optical links.[45] SDA may have awarded 3 contracts totalling $1.8 billion to 3 firms, each for 42 satellites to be launched by September 2024.[61][90] However, there was a funding constraint in the FY2022 budget.[94][95][96]
Tracking layer handles launched items,[97] connects to existing user equipment[16][94][92][98][99] Two contractors will each build 14 satellites for the Tranche 1 Tracking Layer as of 16 July 2022; these satellites will be in Low Earth Orbit (LEO) by 2025; hundreds of satellites are planned for the Tracking layer.[100] The Tracking Layer is capable of tracking hypersonic missiles throughout their flight, by their heat signatures.[100][101][62][102]
Custody layer[103] handles items not yet launched from objects as big as a truck,[104] connects to existing user equipment[16]
Earth'ssatellites in:Low Earth orbit— LEO (blue);Medium Earth orbit— MEO (green);Cislunar distances (red): If one were to hold ablue marble out at arm's length, one would see Earth's size and shape from the perspective of the astronauts travelling to the Moon.
SDA's initial launch of 10 satellites (denoted Tranche 0)[c] had been scheduled for December 2022; however tests of 8 of these satellites indicated that each had anoisy power supply. The contractor, York Space Systems retrofitted filters on the 8 satellites at no cost to the government; the initial launch was delayed to March 2023, including the 8 retrofitted by York Space Systems.[115][38]
On 2 April 2023 the first 10 satellites of Tranche 0 were launched into low earth orbit, as planned. These satellites will demonstrate the responsive (low latency) communication links of the Transport layer of the Proliferated Warfighter Space Architecture (PWSA). An initial checkout of the satellite bus and mission[c] payloads is the current priority.[115] The second Tranche 0 launch, carrying 13 more satellites, took place on 2 September 2023.[117] Of the 18 initially scheduled payloads one Transport satellite built by York has been excluded to conduct software tests, while the four Tracking satellites built byL3Harris had been kept on the ground by production delays and were launched later as rideshare payloads of aUSSF-124 mission in February 2024.[118]
SDA began as adirect reporting unit (DRU) of DoD's USD(R&E): research and engineering.[b] By design,[121] the functions foracquisition and sustainment (A&S) are the responsibility ofanother under secretary of defense —the USD(A&S); this separation of function decouples the technology development of a working prototype system, even the systems as complicated as those taken on by the SDA, from overcomplication induced by the processes of the DoD.
The SDA has relied heavily on "Section 804" Mid-Tier Acquisitions (MTAs) to avoid traditional defense procurement requirements. SDA has been able to forgo a number of reporting activities by breaking up larger programs into numerous two-year rapid fielding projects that each qualify as MTAs. Members of Congress and theGovernment Accountability Office have said this obfuscates costs and limits transparency. The FY23 omnibus appropriations act, signed byPresident Joe Biden on 29 December 2022, levies new reporting and certification requirements on the Pentagon regarding the use of MTAs and other rapid prototype programs. Industry participants such asMITRE Acquisition Chief Pete Modigliani have said the new requirements would "drastically impede DoD’s rapid acquisition abilities" for SDA and other programs.[122]
^abcdefghThe name change of the constellation from NDSA to PWSA —'proliferated warfighter space architecture'— will have no impact to the SDA mission.[89]
^ab"The OUSD(R&E) will develop critical technologies, rapidly prototype them, and conduct continuous campaigns of joint experimentation to improve on those technologies and deliver capabilities", —Hon.Heidi Shyu, head of the office of the undersecretary of defense for research and engineering (OUSD(R&E)).[119][120]
^abcdefTranche 0 will demonstrate the feasibility of
^abcSpace development agency (SDA) provides the PWSA wide field of view (WFOV) sensors;Missile defense agency (MDA) provides theHypersonic and Ballistic Tracking Space Sensor (HBTSS) sensors, (i.e., the Medium Field of View (MFOV) sensors). The WFOV sensors provide cueing data to the MFOV sensors, which are more sensitive and provide tipping data to theearth-based interceptors.[108] as cited in USNI News.[109] Two WFOV satellites were launched as part of the inititial Tranche 0.[38]
^In September 2021 the Space Development Agency approved design plans for its new missile warning satellites, which will be capable of detecting and tracking hypersonic weapons.[79][62]
L3Harris Technologies announced that the Space Development Agency has approved the company’s proposed design for a missile tracking satellite.[80] A production contract for 16 Tranche 1 Tracking satellites to track hypersonic missiles, for launch in 2025, was approved.[81]
SpaceX will build 4 satellites for the Tranche 0 tracking layer.[38]
^In Remote Sensing, Tipping and Queuing (Cueing) is a technique for tracking and monitoring fast-moving objects, using multiple sensors of multiple modalities (for example electro-optical and radar sensors). One sensor with a wide field of view might detect, acquire, and even track an object of interest (the 'target'); that sensor would 'tip' another sensor with the tracking information for that target. The next sensor, say with point defense capability, might then take the 'cue' to narrow the tracking box around the target, to build more accurate tracking information, to tip yet another defense system, and so forth.SeeAutomatic identification system (AIS)[107]
^abBaucom, Donald (2004)."The Rise and Fall of Brilliant Pebbles"(PDF).The Journal of Social, Political, and Economic Studies.29 (2).Archived(PDF) from the original on 2023-03-07. Retrieved2023-01-03.
^"2022 National Defense Strategy"(PDF). Office of the Secretary of Defense. 27 October 2022.Archived(PDF) from the original on 17 January 2023. Retrieved10 November 2022.
^abTheresa Hitchens(28 Oct 2021) SDA Scraps, Relaunches Data Transport Satellite Bidding After ProtestArchived 28 October 2021 at theWayback Machine Tranche 1: T1TL of Aug 2021 was rescinded: "126 satellites [each] with Ka-band space-to-ground communications link, four optical communications terminals, a Link 16 payload (which is the current standard for machine-to-machine communications link among US and allied weapon systems), and a battle management, command, control and communications (BMC3) compute and storage module"; T1TL RFP was reissued 28 Oct 2021. T1TL terms were replaced with OTA authority instead. Proposals were due 24 Nov 2021.
^Center for Strategic & International Studies(7 Feb 2022) Complex Air Defense: Countering the Hypersonic Missile ThreatArchived 23 September 2022 at theWayback Machine Dr. Tom Karako, Director of the CSIS Missile Defense Project; Ms. Kelley Sayler, CRS; Dr. Gillian Bussey, Director of the Joint Hypersonics Transition Office; Dr. Mark Lewis, Executive Director of NDIA's Emerging Technologies Institute; Mr. Stan Stafira, Chief Architect at the Missile Defense Agency (MDA)
^Secretary of the Air Force Public Affairs(19 Sep 2022) Air Force taps Brig. Gen. Luke Cropsey to head new integrated C3 battle management programArchived 23 March 2023 at theWayback Machine Command, Control, Communications and Battle Management (C3BM). USAF general Cropsey will have the authorities required to ensure integration of all C3BM related programs throughout the DAF, as a core contribution to the Department of Defense's broader Joint All Domain Command and Control (JADC2) effort. [Integrating] PEO will also have responsibility for the Advanced Battle Management System (ABMS).
_Transport_layer.webp)
![Fred Kennedy[123]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aFred_G._Kennedy_III.jpg)
![Derek M. Tournear[124]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aDerek_M._Tournear.jpg)
![Lieutenant General Philip Garrant[127]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aLt_Gen_Philip_A._Garrant_(2).jpg)
![William B. Blauser[129]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aNo_image.png)
This article incorporates text from this source, which is in thepublic domain.
