U.S. Space Systems Command Wednesday evening launched the final four Tranche 0 satellites in the Space Development Agency’s (SDA) demonstration of low-Earth orbit capabilities for data transport and missile tracking, and the Missile Defense Agency’s (MDA) first two prototype spacecraft with sensors to evaluate warning and tracking of hypersonic and ballistic missile threats.
The liftoff of the U.S. Space Force-124 mission from Space Launch Complex 40 at Cape Canaveral Space Force Station, Fla., aboard a SpaceX Falcon 9 launch vehicle carried five spacecraft built by L3Harris Technologies [LHX], four wide-field-of-view Tranche 0 Tracking Layer birds for SDA and one Hypersonic and Ballistic Tracking Space Sensor (HBTSS) satellite for MDA, and one HBTSS bird supplied by Northrop Grumman [NOC].
“Launching our Tracking satellites into the same orbit with the MDA HBTSS satellites is a win for both agencies,” Derek Tournear, SDA’s director, said in a statement prior to the launch. “We’ll be able to look at test targets from the same orbit at the same time, so that we can see how the two sensors work together.”
The Defense Department has not yet provided an update on the status of the satellites. SpaceX’s first stage rocket successfully returned to a landing pad.
The L3Harris Tranche 0 satellites will also be the first to include optical communications terminals supplied by CACI International [CACI].
The six satellites were originally expected to be launched last year. L3Harris and Northrop Grumman received the HBTSS prototype sensor satellite contracts in January 2021.
The Tranche 0 Tracking and Transport Layer satellites are referred to as the “warfighter immersion tranche” that will be used in military exercises and demonstrations to give warfighters a look at the capabilities that will be resident in the subsequent operational tranches, beginning with Tranche 1.
The first Tranche 1 Transport Layer satellites are expected to be launched later this year followed by the launch of the first Tranche 1 Tracking Layer spacecraft in 2025.
“In Tranche 1, SDA will fly both sensor types as an operational system, medium-field-of-view demonstrating fire control based on HBTSS design, and wide-field-of-view doing warning and tracking, based on T0 tracking design,” Tournear stated.
The Tranche 0 satellites will give warfighters and vendors an opportunity to learn, and inform and bolster the supply chain for this program, a senior SDA official told reporters during a background briefing on Tuesday. Once the wide field of view payloads are checked out and deemed ready, the satellites will be ready to be used in demonstrations, the official said.
MDA and SDA said the testing and checkout of the HBTSS prototypes will take a few weeks to “ensure the satellites are operating and integrating with the missile defense system and other mission areas.” MDA says the HBTSS sensors will allow “birth-to-death” tracking of missile threats.
If the latest Tranche 0 satellites are placed into orbit, SDA will have 19 Transport and eight Tracking Layer satellites in space. One Transport satellite will stay on the ground for use as a software testbed.
The low-latency Transport Layer satellites will provide secure, multi-band global communications for warfighters, will be the space backbone for Joint All Domain Command and Control infrastructure, and enable sensor-to-shooter connectivity, SDA says. The Tracking Layer satellites will provide constant global coverage of indications, detection, warning, tracking, and identification of advanced missile threats, including hypersonic missiles, the agency says.
Combined, the Tracking and Transport Layer spacecraft in low-Earth orbit, and related ground system capabilities, make up SDA’s Proliferated Warfighter Space Architecture.
Lockheed Martin [LMT], SpaceX, and York Space Systems also built and delivered Tranche 0 satellites.