Falcon 9 | SDA Tranche 1 Transport Layer D — Launch 30 Sep 2026

When is the launch?

A SpaceX Falcon 9 Block 5 is scheduled to launch the SDA Tranche 1 Transport Layer D mission no earlier than 00:00 UTC on 30 September 2026. The flight will lift off from Space Launch Complex 4E (SLC-4E) at Vandenberg Space Force Base in California.

The status is currently TBD, meaning the date and time may shift as the mission approaches. Government-payload launches like this one are subject to range availability and payload readiness, so check the rocket launch schedule for the latest timing before you plan to watch.

What is the payload?

This mission carries a batch of satellites for the Space Development Agency (SDA) Tranche 1 Transport Layer. The Transport Layer is the backbone of the SDA's Proliferated Warfighter Space Architecture — a low Earth orbit mega-constellation designed to provide resilient, low-latency data relay and communications to military users worldwide.

SDA's approach relies on many relatively small satellites spread across multiple orbital planes, connected by optical inter-satellite laser links. Tranche 1 represents the first operational layer of that architecture, building on the earlier Tranche 0 demonstration satellites. Deploying these spacecraft into their proper planes typically requires several dedicated launches, and this Transport Layer D flight is one segment of that broader deployment campaign.

Once deployed, you'll be able to follow the new satellites as they spread into their operational orbits on the Cosmik live 3D satellite map.

How to watch live

SpaceX typically begins its live webcast roughly 15 minutes before liftoff, streaming on its official channels. Because this is a national-security-related payload, coverage may be abbreviated after the initial ascent, but the launch and early flight phases are usually shown.

• Confirm the current launch time on the SpaceX launch hub.
• Set a free launch alert on Cosmik so you're notified as the countdown nears.
• Tune in about 15 minutes early to catch the pre-launch checks and liftoff.

For West Coast viewers, launches from Vandenberg can sometimes be visible from surrounding areas depending on weather and time of day.

Why launch from Vandenberg?

Vandenberg Space Force Base is the primary U.S. West Coast launch site and is ideal for missions heading into polar and high-inclination orbits, which are common for LEO constellations that need global coverage. SLC-4E is SpaceX's dedicated Falcon 9 pad on the base and has supported numerous Starlink, government, and commercial rideshare missions.

About the Falcon 9 Block 5

The Falcon 9 Block 5 is the latest and most flight-proven version of SpaceX's partially reusable two-stage rocket. Its first stage returns to Earth for a landing — either on a droneship downrange or back near the launch site — enabling rapid reuse. This reusability has made Falcon 9 the workhorse of the modern launch industry, flying dozens of missions per year.

About the Space Development Agency

The Space Development Agency is a U.S. Department of Defense organization tasked with rapidly fielding a proliferated constellation in low Earth orbit. Its layered architecture separates functions such as data transport (Transport Layer) and missile tracking (Tracking Layer) across dedicated satellite tranches.

Will the launch succeed?

We'll update our latest launch news with the outcome after liftoff, including first-stage landing results and payload deployment status. Until then, the mission remains a scheduled event with a TBD launch window.

Launch data for this mission is sourced from The Space Devs Launch Library.

Follow the launch live on Cosmik

Track the countdown, watch the Falcon 9 climb toward orbit, and then follow the deployed SDA satellites on our real-time 3D map of the solar system and every satellite in orbit. Enable free launch alerts so you never miss liftoff — and explore how to track satellites overhead from anywhere.