Falcon 9 | SDA Tranche 2 Transport Layer A — Launch 31 August 2026

When is the launch?

SpaceX is scheduled to launch a Falcon 9 Block 5 carrying the SDA Tranche 2 Transport Layer A payload no earlier than 00:00 UTC on 31 August 2026. The mission will lift off from Space Launch Complex 4E (SLC-4E) at Vandenberg Space Force Base, California. The status is currently listed as TBD, so the exact liftoff time may shift as range schedules and payload readiness are confirmed.

You can check the current time and any changes on our rocket launch schedule, which updates automatically from live launch data.

How to watch the launch live

SpaceX typically begins its webcast a few minutes before liftoff on its official channels. Because this is a national security-related payload, coverage may be abbreviated compared with commercial flights, sometimes ending shortly after stage separation.

To follow the mission in context, watch it on Cosmik's live 3D solar system and satellite map, and track the vehicle and its deployed satellites in real time. You can also enable free launch alerts so you never miss the countdown.

Quick facts

What is the payload?

The Space Development Agency (SDA) is a component of the United States Space Force tasked with building a resilient, proliferated constellation of satellites in low Earth orbit known as the Proliferated Warfighter Space Architecture. This architecture is delivered in incremental "Tranches."

The Transport Layer forms the backbone of that architecture — a mesh network of satellites equipped with optical inter-satellite links designed to relay data quickly across the globe and connect sensors to shooters. Tranche 2 expands on the capabilities demonstrated by earlier Tranche 0 and Tranche 1 batches, increasing coverage and network capacity.

SDA follows a strategy of frequent, spiral-development launches, meaning satellites are procured from multiple vendors and launched in batches to keep the constellation modern and hard to disable. This mission adds to that growing network in low Earth orbit.

Why launch from Vandenberg?

Vandenberg Space Force Base on California's Central Coast is the primary U.S. West Coast launch site for missions heading into polar and Sun-synchronous orbits. Launches head south over the Pacific Ocean, making it ideal for constellations that require high-inclination coverage — exactly what a global relay network like the Transport Layer needs.

SLC-4E is SpaceX's dedicated Falcon 9 pad at Vandenberg and has supported a high cadence of Starlink, commercial, and national security missions. Explore more launches from the site on our Vandenberg launch hub.

About the Falcon 9 Block 5

The Falcon 9 Block 5 is SpaceX's workhorse two-stage rocket and the most-flown orbital vehicle in operation. Its reusable first stage returns to a landing zone or an autonomous droneship, and boosters routinely fly many times. For West Coast missions, first-stage recovery is often performed on a droneship stationed in the Pacific.

Falcon 9's reliability and rapid turnaround have made it the launch vehicle of choice for many SDA missions, supporting the agency's goal of deploying satellites on an aggressive schedule. See more upcoming SpaceX flights on our SpaceX launch hub.

How to track the satellites after launch

Once the Transport Layer satellites are deployed, you'll be able to follow them alongside thousands of other objects in orbit. Learn more in our guide on how to track satellites, and keep up with the latest missions on our space launch news page.

Where to learn more

• Falcon 9 (Wikipedia)
• SpaceX (Wikipedia)
• Vandenberg Space Force Base (Wikipedia)
• Launch data source: The Space Devs

Follow the launch live on Cosmik

Don't miss liftoff — follow the Falcon 9 and SDA Tranche 2 Transport Layer A mission on Cosmik's real-time 3D map, enable free launch alerts, and watch the newly deployed satellites join the constellation in orbit.