WASHINGTON — The Space Development Agency (SDA) today launched the first batch of its Transport Layer satellites with “operational” capacity to provide military users with text and data communications, according to agency officials.
The 21 Transport Layer Tranche 1 (TLT1) satellites will enable “beyond-line-of site communications in contested and austere environments,” Acting SDA Director Gurpartap “GP” Sandhoo told reporters on Tuesday.
“So, this is the first time we’ll be able to start working with our with our COCOMs [combatant commands], our joint force, to start integrating space into their into the operations, and getting the warfighters used to using space from this construct. This is different than how it has been done in the past,” he said. “This is direct downlink to warfighters.”
The launch was originally slated for September 2024, then subsequently was pushed back to late 2024/early 2025.
The TLTI eventually will comprise 126 satellites in low Earth orbit linked together via optical intersatellite terminals, which will be able to provide regional connectivity initially for Indo-Pacific Command. Northrop Grumman, Lockheed Martin and start-up York Space Systems all won shares of a $1.8 billion contract award in February 2022.
Built by York, the first 21 satellites can carry the military equivalent of “text messages” to forces on the ground, in the air and at sea via multiple Link 16 antennas (the ubiquitous standard NATO data link). They also can beam video via K-band radio frequency broadcasts and a laser downlink, Dirk Wallinger, York’s CEO, told Breaking Defense.
The TLT1 variant “has kind of a situational awareness order of magnitude type of capability, and then it does have the ability for large bulk transfers of information,” he said.
Outgoing SDA Director Derek Tournear told Breaking Defense in an exclusive interview that the successful demonstration during testing of the laser downlink on the York birds was an important first. (Tournear left the agency on Monday to take up a position at Auburn University.)
“[L]aser communication … is a really good way to move a lot of data from space to ground. Now, it obviously is affected by weather, so it’s not something that can be relied upon all the time — but we demonstrated that we can do that. That was the first time a very affordable, commoditized, if you will, commercial optical comm terminal was used to go from space to ground,” he said.
Sandhoo said that the satellites that went up today will be ready for operational use and experimentation within about six months, following a battery of testing.
Under SDA’s current Proliferated Warfighter Space Architecture (PWSA) concept, the TLT1 satellites would be followed by another 200-plus Transport Layer Tranche 2 (TLT2) satellites, made up of three variants called Alpha, Beta and Gamma. Together, the 192 Alpha and Beta variants — being built by Lockheed Martin, Northrop Grumman, York and Rocket Lab — will be integrated into the TLT1 constellation to provide worldwide connectivity. SDA plans to begin launches of those variants, starting with Beta birds, in September 2026.
The agency originally planned to develop 44 Gamma variants to contribute an “advanced tactical data link” to the agency’s fire control experiments. SDA subsequently decided to build only 20 Gamma variants and instead add 18 Beta variants.
SDA in August 2024 awarded two prototype agreements for the Gamma worth approximately $424 million in total to York and Tyvak Nano-Satellite Systems, a subsidiary of Terran Orbital, for 10 satellites apiece. (Terran Orbital was bought by Lockheed Martin in October.) Tyvak’s contract, however, was contested by Viasat.
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Sandhoo said that while SDA in February had launched a recompete of the Tyvak contract following Viasat’s protest, a decision was made “about two months ago” to cancel that new bidding process. He explained that a re-evaluation of the Gamma effort showed that planned experiments could be completed using only the 10 satellites already in hand (built by York).
Meanwhile, SDA’s planned next-generation Tranche 3 Transport Layer satellites are on hold, as the Department of the Air Force and the Space Force weigh whether to move forward. While the Defense Department long has touted the Transport Layer as the linchpin for its Joint All Domain Command and Control initiative to connect sensors-to-shooters, DoD is now looking at replacing the Transport Layer with a classified project dubbed MILNET based on acquiring SpaceX Starshield satellites and services under a government owned, contractor operated project.