The Space Development Agency will begin launching its Tranche 1 Transport Layer in 2024, but already is developing the follow-on Tranche 2 configuration. (Image: Northrop Grumman)
WASHINGTON — Fresh off its first successful launch, the Space Development Agency next week intends to solicit industry bids for the first 72 improved data relay satellites in a planned constellation that will, for the first time, connect warfighters around the world to a secure low Earth orbit communications network, according to SDA Director Derek Tournear.
Tournear told the Mitchell Institute’s Space Power Forum today that there will be a total of 216 Transport Layer satellites orbited for what the agency calls its Tranche 2 configuration, which will begin launching in 2026.
Those satellites, he said, “will make the entire architecture globally persistent.”
SDA’s Transport Layer ultimately will comprise some 300 to 500 satellites interconnected via laser cross-links to provide users with high-speed, high-volume, low-latency (i.e. minimal delay) data transmission — a network that will provide a foundational capability to substantiate the Pentagon’s Joint All Domain Command and Control (JADC2) concept.
Somewhat confusingly, Tranche 2 actually represents SDA’s third set of satellites designed under its spiral development approach, and like its predecessors, will include not just Transport Layer satellites but also missile warning/missile tracking satellites for its planned Tracking Layer constellation.
SDA on April 2 successfully launched 10 of 28 planned Tranche 0 demonstration satellites: eight for the Transport Layer and two for the Tracking Layer. The remaining Tranche 0 satellites, 12 Transport Layer and six Tracking Layer, will be lofted in June.
In February 2022, the agency awarded $1.8 billion in contracts to York Space Systems, Northrop Grumman and Lockheed Martin for development of a follow-on set of 126 Transport Layer satellites for the Tranche 1 constellation. Tournear today explained that Tranche 1 is the first operational data relay constellation for SDA, which will provide “regional persistency” — meaning they can be “turned on” to transmit data over one theater at a time. SDA expects to begin launching the Tranche 1 satellites in September 2024.
The Trance 2 Transport Layer constellation will utilize improved designs, Tournear said, with three different “instantiations” called Alpha, Beta and Gamma — each carrying slightly different payload sets.
Next week’s request for proposals covers what the agency is calling the Tranche 2 Beta satellites, he said, which will carry optical intersatellite links for cross-satellite communications and a UHF Tactical Satellite Communications (TacSATCOM) downlink for “tactical users.”
That RFP will be closely followed by another for 100 Alpha version satellites, Tournear said, carrying laser crosslinks, a Ka-band communications downlink, on-board battle management processing and a Link 16 data link for machine-to-machine connection with current platforms such as aircraft and ships.
Finally, he said, around the turn of the year, SDA will issue the RFP for 44 Gamma variants that will resemble the Beta configuration but with the addition of “advanced waveforms.”
