SpaceX has launched a batch of 10 communications and missile tracking satellites on the Tranche 0 Flight 1 mission for the Space Development Agency (SDA) on Sunday, April 2, 2023, at 7:29 AM PDT (14:29 UTC).
The flight took off from launch site SLC-4E at Vandenberg Space Force Base in California. The satellites were placed into a 1,000 km orbit, inclined 80 degrees.
The Falcon 9 launch vehicle used booster B1075-2, which previously launched the Starlink 2-4 mission. After separating from the second stage, the booster returned to Landing Zone 4 at the launch site. The Falcon 9 second stage will be deorbited south of South Africa a couple of hours after the launch.
This is the first of two launches for SDA’s Tranche 0, the demonstration phase of the new Proliferated Warfighter Space Architecture (PWSA), formerly known as the National Defense Space Architecture. SpaceX was awarded a 150 million dollar contract on Dec. 31, 2020, for two flights of Falcon 9 to launch the 28 satellites.
The 10 payloads on this flight include eight Transport Layer satellites from York Space Systems and two Tracking Layer satellites from SpaceX. The second launch in June will carry the rest of Tranche 0: two Transport Layer satellites from York Space Systems, eight Transport Layer satellites from Lockheed Martin, two Tracking Layer satellites from SpaceX, and four Tracking Layer satellites from L3Harris.
The SDA was established in March 2019 to serve as a “constructive disrupter” for the Department of Defense (DoD) space acquisition. SDA’s focus is to perform spiral development of PWSA, a proliferated low Earth Orbit constellation, that will provide communications, missile warning/tracking, and other functions to the DoD by deploying many smaller, less expensive, and faster to produce spacecraft than traditional DoD satellite systems. SDA became part of the Space Force on Oct. 1, 2022.
The SDA’s motto is “Semper Citius,” meaning always faster. The goal is to regularly field new batches of satellites that improve in capability over time, rather than design exquisite systems that would likely come in years late and over budget. Every two years the SDA will procure a new Tranche of satellites that can include multiple layers performing different functions.
Each tranche is openly competed so that new vendors have an opportunity to participate in the program. Building a constellation of interoperable satellites from multiple vendors is a key goal of the program. This has been a boon to several suppliers of small satellite buses and optical inter-satellite links (OISL) that have been able to begin producing higher volumes of its products. The constellation will eventually include hundreds of satellites in near-polar orbits at 1,000 km altitude.
Transport Layer satellites are the backbone of the network, carrying RF and optical communication payloads, with the optical links forming a mesh network. There are tactical Link 16 payloads to communicate with forces in the field, as well as other RF payloads to communicate with ground stations. For Tranche 0, there are two types of Transport satellites: Group A (13 satellites) has two OISL as well as RF communications, while Group B (seven satellites) has two OISL and Link 16 tactical data links. In Tranche 1 the Transport satellites will have more OISL and tactical data links on each spacecraft. This first launch has five Group A and three Group B Transport satellites.
Tracking Layer satellites serve an overhead persistent infrared imaging function for missile warning and tracking with a wide field of view payload, and can communicate with the Transport Layer satellites over optical links. They are designed to track advanced missiles including hypersonic glide vehicles.
Starting with Tranche 1, each spiral will also include some experimental satellites used to mature new payloads for communications, remote sensing, position navigation and timing (PNT), and more advanced onboard computing.
Tranche 0 (the Warfighter Immersion tranche) is focused on demonstrating the procurement, deployment, and operation of a minimum viable product. The agency moved quickly to begin procuring this first tranche, with contracts for the Transport Layer, Tracking Layer, and launch awarded by the end of 2020.
The Tranche 0 Transport Layer contracts for 20 satellites were awarded on Aug. 31, 2020, at the cost of about $280 million; this contract awarded 10 satellites each to Lockheed Martin ($187 million) and York Space Systems ($94 million). The Tracking Layer contracts for eight satellites were awarded on Oct. 5, 2020, at a total cost of about $350 million, with four satellites each to L3Harris ($194 million) and SpaceX ($149 million). While most of the satellites are sized to be mounted on ESPA rings to form the payload stack, the SpaceX satellites are larger and will be placed on top of the ESPA rings.
Ground systems for Tranche 0 are being provided through collaboration with the Naval Research Laboratory, which also supports interoperability testing of the OISL hardware from various vendors.
Trials of the Tranche 0 Transport Layer will include testing of Link 16 functionality at the Eglin Test and Training Complex in Florida, as well as exercises with the Marines in the USINDOPACOM region later in the year. After going through calibration, the Tracking Layer will initially look for targets of opportunity, then will be used to track US hypersonic missile tests in the spring of 2024. The goal is to let future users get their hands on these systems so that they can start developing procedures ahead of the deployment of the first operational tranche starting in late 2024.
Future tranches are already underway, with all of the contracts for Tranche 1 awarded and procurement of Tranche 2 in its early stages.
LHA map for #SDA-0A mission from VSFB SLC-4E NET 30 Mar 14:29 UTC, altern. 31 Mar to 05 Apr based on issued NOTAM/NOTMARs. LZ-4 landing for booster 1075.2. Estimated fairing recovery position approx. 490km downrange. S2 reentry area south of Cape Town. https://t.co/BpJZ15cY0J pic.twitter.com/Y3xyKmaGEb
— Raul (@Raul74Cz) March 29, 2023
Tranche 1 is to provide an initial warfighting capability. Features of Tranche 1 are regional persistence for tactical data links, advanced missile detection, and beyond-line-of-sight targeting. The launches will be split up between United Launch Alliance and SpaceX through the NSSL Phase 2 program, with flights starting in September 2024 and occurring monthly for about a year. The flights will start with the six planes of Transport satellites, 21 on each flight, and then continue with more launches carrying Tracking and Tranche 1 Demonstration and Experimentation System (T1des) spacecraft.
The Tranche 1 Transport Layer contracts were awarded on Feb. 28, 2022, for 126 satellites (approximately $1.8 billion in total), 42 each from Lockheed Martin ($700 million), Northrop Grumman ($692 million), and York Space Systems ($382 million). These provide more capability than the Tranche 0 satellites at a similar price.
The initial Tranche 1 Tracking Layer contracts were awarded on July 18, 2022, with 28 satellites (approximately $1.3 billion) split between L3Harris ($700 million) and Northrop Grumman ($617 million). Each of those contractors will provide two planes of seven satellites. In March 2023, another award was made to Raytheon ($250 million) for a fifth plane of 7 satellites that will launch in late 2025. The Tranche 1 Tracking satellites are about twice the size of the Transport satellites.
The Tranche 1 Operations and Integration contract was awarded to General Dynamics ($324 million), along with Iridium, to establish the ground Operations & Integration segment for Tranche 1. This will include setting up control centers for SDA in Grand Forks and at Redstone Arsenal in Alabama.
The T1DES contract of about $200 million was awarded to York Space Systems on Sept. 30, 2022. These 12 satellites will augment the Tranche 1 Transport Layer constellation with demonstration and experimentation of tactical satellite communication and integrated broadcast service capabilities from low Earth orbit.
Tranche 2, following two years after Tranche 1, will provide global persistence for all of the functionality in Tranche 1 and incorporate lessons learned from operating Tranche 0. The procurement process has already begun for this tranche.
(Lead image: Falcon 9 launches from SLC-4E on SDA Tranche 0 Flight 1. Credit: SpaceX)