![\"\"](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/09\/20250909_SDA_T1TL-A_stack.jpg\")
21 satellites manufactured by York Space Systems for Space Development Agency\u2019s upcoming Tranche 1 Transport Layer launch. Image: York Space Systems<\/p>\n21 satellites manufactured by York Space Systems for Space Development Agency\u2019s upcoming Tranche 1 Transport Layer launch. Image: York Space Systems<\/p>\n
The first in a series of launches supporting a burgeoning satellite constellation for the Space Development Agency (SDA) is set to take flight Wednesday morning from Vandenberg Space Force Base in California.<\/p>\n
The SDA was formed as an independent agency 2019 with the goal of safeguarding the United States against hypersonic weapons and offering a network of satellites and ground support systems that could unify the Department of Defense\u2019s capabilities across a \u201cresilient, threat-driven space surveillance and communications architecture,\u201d according its establishing memorandum<\/a>. It became a part of the U.S. Space Force in October 2022.<\/p>\n The 21 satellites, built by York Space Systems, are the first, fully operational spacecraft for the constellation known as the Proliferated Warfighter Space Architecture (PWSA). It was formerly called the National Defense Space Architecture (NDSA), but the name was changed in 2023.<\/p>\n The SDA said it was renamed \u201cto more specifically reflect the agency\u2019s mission to deliver\u00a0needed space-based capabilities to the joint warfighter to support terrestrial missions through development, fielding, and operation of a proliferated low Earth orbit (pLEO) constellation of satellites.\u201d<\/p>\n SpaceX is targeting launch of its Falcon 9 rocket for the Tranche 1<\/a> Transporter Layer mission from Space Launch Complex 4 East at 7:12 a.m. PDT (10:12 a.m. EDT \/ 1412 UTC).<\/p>\n Spaceflight Now will have live coverage beginning about 30 minutes prior to liftoff.<\/p>\n \ufeff<\/p>\n While a specific launch weather forecast wasn\u2019t issued publicly ahead of the launch, SDA Deputy Director Gurpartap \u201cGP\u201d Sandhoo said on Tuesday mission teams polled \u2018go\u2019 to proceed with the final prelaunch activities ahead of the Wednesday morning launch attempt.<\/p>\n This mission was awarded to SpaceX as part of the National Security Space Launch (NSSL) Phase 2 contract, which is managed by the U.S. Space Force\u2019s Space Systems Command (SSC). It was one of three missions awarded to SpaceX as part of a $309.7 million agreement.<\/p>\n For this first Tranche 1 mission, SpaceX will use the Falcon 9 first stage booster 1093, which will be flying for a sixth time. Its previous five flights were all in support of SpaceX\u2019s Starlink constellation.<\/p>\n A little more than 8.5 minutes after liftoff, B1093 will target a propulsive landing on SpaceX\u2019s drone ship called \u2018Of Course I Still Love You,\u2019 which will be positioned in the Pacific Ocean.<\/p>\n As with many national security missions a full deployment timetable was not released, but an SDA official said the 21 satellites would be deployed into a polar orbit in batches starting about an hour after launch, noting there are several minutes between each deployment sequence.<\/p>\n Coming soon to (war) theaters<\/p>\n The Tranche 1 Transport Layer (T1TL) is the first batch of operational satellites supporting the SDA\u2019s PWSA constellation. It comes after nearly two dozen demonstration satellites were launched across three Falcon 9 flights between 2023 and 2024 as part of Tranche 0.<\/p>\n Breaking down some of the jargon, the SDA defines a \u201ctranche\u201d as the generation or iteration of satellites. Meanwhile the agency said a \u201clayer\u201d signifies \u201ca particular function of the architecture that delivers or enables a warfighting capability.\u201d<\/p>\n In this instance, the SDA said its Tracking Layer \u201cwill provide a mesh network comprised of communication satellites that connect to one another and to other space vehicles and ground stations via optical intersatellite links (OISLs).\u201d<\/p>\n That \u201cmesh\u201d refers to the optical lasers used to connect the satellites in orbit between one another as well as to ground stations around the world.<\/p>\n \u201cThe Tracking Layer and Custody Layer provide sensing functions for advanced missile threats and time-critical land and maritime targets, and connect to the Transport Layer to provide threat indications and targeting data to our warfighters in real time,\u201d the SDA stated on its website.<\/p>\n During a prelaunch briefing on Tuesday, Sandhoo described the Transport Layer as a type of \u201crelay\u201d that helps extend sensitive, tactical communications beyond a line of sight. Right now, that\u2019s a limitation of Link 16 radios<\/a>, which are a secure communications system used by NATO and its partners.<\/p>\n \u201cNow (following the incorporation of this technology), you\u2019re able to talk not only to within a couple of miles with your Link 16 radios,\u201d Sandhoo said. \u201cWe can use space to go, let\u2019s say, go from Hawaii out to Guam using those tactile radios, using a space layer\u2026 as a relay.\u201d<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/09\/20250909_SDA_T1TL_satellites_encapsulated.jpg\")
The 21 satellites for the Space Development Agency\u2019s Tranche 1 Transporter Layer are brought to the pad at Space Launch Complex 4 East at Vandenberg Space Force Base. Image: Derek Tournear via LinkedIn<\/p>\n![\"\"](\"https:\/\/www.newsbeep.com\/uk\/wp-content\/uploads\/2025\/09\/20250909_Meink_Tranche-1_visit.jpeg\")
Secretary of the Air Force Troy Meink along with Senator Kevin Cramer (R-N.D.) pose with Vandenberg SFB leadership in front of the Space Development Agency\u2019s Tranche 1 satellites at a satellite processing facility at Vandenberg Space Force Base, Calif., Aug. 28, 2025. Tranche 1 is slated to launch from the Vandenberg Spaceport no earlier than Sept. 10. This will be the first 21 of 126 Tranche 1 Transport Layer satellites going to low-Earth orbit to deliver next-gen capability to the joint warfighter to support terrestrial missions through the Proliferated Warfighter Space Architecture. Image: U.S. Air Force photo by Staff Sgt. Daekwon Stith<\/p>\n