New U.S. military satellite constellation takes shape with first launch from Vandenberg SFB

The Space Development Agency took a big step in realizing a new satellite constellation to support the various branches of the U.S. military and its allies.

On Wednesday, the SDA, part of the U.S. Space Force (USSF), celebrated the successful launch and deployment of 21 communication satellites that are a part of the first generation or Tranche 1 of its Proliferated Warfighter Space Architecture. This was the first in a series of six launches for what it calls the Transport Layer of space vehicles.

The SDA defines a “layer” as the primary function of that collection of satellites.

“The start of Tranche 1 delivery, just over six years since SDA stood up as an agency, is a remarkable accomplishment highlighting the speed at which the agency moves,” said SDA Acting Director Gurpartap ‘GP’ Sandhoo in a post-launch statement. “More than that, as the PWSA begins to support military operations, it will enhance our strategic advantage by serving the joint warfighting force with operational capabilities previously thought infeasible from LEO (low Earth orbit).”

The mission began with a SpaceX Falcon 9 launch from Vandenberg Space Force Base. An on time liftoff at 7:12 a.m. PDT (10:12 a.m. EDT / 1412 UTC) was followed by a successful recovery of the first stage booster on a drone ship in the Pacific Ocean less than nine minutes later.

Launch success!Thanks to the great team, we had liftoff of the SDA T1TL-B mission on a SpaceX Falcon 9 launch vehicle. Capabilities delivered by this launch will help pave the way to the future of our integrated space-ground missile warning architecture. https://t.co/tiJU9OFY8M pic.twitter.com/Fo3JpQUvMg

— Space Systems Command (@USSF_SSC) September 10, 2025

This was the sixth mission launched by SpaceX as part of the National Security Space Launch (NSSL) Phase 2 contract out of the 23 missions it was awarded by the USSF’s Space Systems Command.

“The NSSL team has been preparing for the start of these higher cadence operations and we are ready and eager for the remainder of SDA’s T1 launches,” said U.S. Space Force Col. Ryan Hiserote, Senior Materiel Leader for Assured Access to Space’s (AATS) Launch Execution Delta. “We’re looking ahead, focused on countering the pacing threats and cementing the launch ops responsiveness needed for the future, right now.”

Across Tranche 1, there are a total of 10 launches, including the one on Wednesday. Those break down to six for the Transporter Layer, with a total of 126 satellites; four for the Tracking Layer with 28 satellites; and there will be four missile defense demonstration satellites as well.

In a prelaunch teleconference, Sandhoo told reporters that the SDA is aiming for a monthly launch cadence to support Tranche 1 of the constellation. Next up will be another batch of Transport Layer satellites, but this time from Lockheed Martin.

Those are projected to launch in the second week of October onboard a Falcon 9 rocket from Vandenberg. The first Tranche 1 Tracking Layer (T1TR) satellites will launch in early 2026.

Across 2023 and 2024, SpaceX launched 27 demonstration satellites as part of a demonstration constellation called Tranche 0. That included 19 Transport satellites and eight Tracking satellites.

New capabilities, further reach

Now that these first 21 Tranche 1 Transport Layer (T1TL) satellites are safely on orbit, the SDA will take the next couple of weeks to go through early operations and checkouts to make sure that all of the systems are working as expected.

“We’ve made a ton of improvements since Tranche 0. As far as our checkout timelines, we’ve learned a ton from Tranche 0,” said Mike Eppolito, SDA’s Chief Program Officer, on Tuesday. “You’re going to see our bus checkout timelines go from months down to days on Tranche 1.”

Tranche 1 will be operated by SDA Space Operations Centers at Grand Forks Air Force Base in North Dakota and Redstone Arsenal in Alabama.

These first T1TL satellites will go through some early testing and then will be used by some early adopters within about four to six months. Sandhoo said that will primarily be the U.S. Indo-Pacific Command, one of six Unified Combatant Commands of the U.S. Armed Forces.

The SDA said the benefit of the T1TL satellites is that they will serve as a kind of relay to allow for greater transmission of sensitive communications that involve military operations. That will be done through the use of military channels, like Link 16, Ka-band radio frequency and optical communications terminals.

Those laser communications come from subcontractor Mynaric, which is in the process of being acquired by Rocket Lab.

“This is the first time we’ll be able to start working with our COCOMs (Combatant Commands), our joint force, to start integrating space into their operations and getting the war fighters used to using space from this construct,” Sandhoo said.

“This is different than how it has been done in the past. This is the first time we’ll have a space layer actually fully integrated into our war fighting operations,” he added. “Space has been around for a long, long time, but most of space has been in the intelligence collection aspect of things: ISR (intelligence, surveillance and reconnaissance) and PNT (position, navigation and timing) and comms. But this is the first time we’ll have space as part of operational fight.”

Each launch represents one plane in a given layer. So the Tranche 1 Transporter Layer will consist of six planes. Sandhoo said the full constellation doesn’t need to be on orbit before they start becoming useful.

“The way the architecture is designed, we build this capacity up one plane at a time. So as the second plane goes up, you’ll have additional capabilities,” Sandhoo said. “So, it kind of scales up and as we keep adding new planes into it, we’ll get to… regional capacity at the end of Tranche 1.”