Space Development Agency Launches 21 Data Transport Satellites on SpaceX Rocket

VANDENBERG SPACE FORCE BASE, Calif.—The Space Development Agency resumed its Tranche 1 launch effort July 16, sending 21 data transport satellites to continue building out a mesh network in low-Earth orbit.

The mission, which flew on a SpaceX Falcon 9 rocket, lifted off from here in the early afternoon, local time. The satellites, built by York Space Systems, will eventually be part of a network of communication spacecraft in LEO providing secure connectivity for military users. Following the launch, the rocket’s first stage landed on SpaceX’s “Of Course I Still Love You” drone ship.

“This launch continues to expand warfighting capability to deliver persistent tactical satellite communication for the warning and tracking of advanced missile threats,” SDA Director Gurpartap Sandhoo, said in a statement. “In close coordination with Space Systems Command and Space Launch Delta 30, the deployment of Tranche 1’s proliferated capability will soon deliver continuous overwatch—neutralizing any first-mover advantage by delivering data to warfighters around the world , nearly instantaneously.”

The launch is just the third Tranche 1 mission and comes after a nine-month pause in SDA’s flight campaign due to technical and operational challenges following the first two launches last fall. Sandhoo told reporters July 14 that SDA and its vendors have been working to implement fixes to satellites on the ground and in orbit to ensure this next batch of spacecraft has a smoother transition to operations.

With this third plane of satellites on orbit, the agency can soon start to deliver “real capability for the warfighter,” he said.

The launch is the second Tranche 1 mission for York, whose first 21 satellites were on the initial flight last September.

“As the nation builds toward the next generation of national security space and missile defense architectures, the demand for satellites at real scale keeps growing, and York is one of the few companies that can actually deliver it,” York CEO Dirk Wallinger said in a statement.

Prior to the launch pause, SDA’s plan had been to launch 154 Tranche 1 satellites over a 10-month period. It’s not clear whether the agency will pursue a similar cadence now or how long it will take to launch the remaining spacecraft. Sandhoo declined to commit to a particular schedule, and instead said his focus is on ensuring the satellites have a clear path to operations rather than hitting an “artificial timeline.”

“The goal here is not to launch on a monthly cadence,” he said. “The goal is to launch and get quickly through the checkout so we can get to operations. And that requires confidence in a system.”

Moving forward, Sandhoo said, the order of the Tranche 1 launches will be based on satellite readiness, and SDA will coordinate all of the satellite processing. He noted that because of the earlier delays, there will likely be an overlap of Tranche 1 and Tranche 2 missions as the latter satellites are scheduled to start launching in fiscal 2027.

“As Tranche 2 satellites get ready for launch, if they are ready to go, we will process them and we’ll get them to orbit,” he said.

While all of the Tranche 1 launches to date have been for SDA’s data transport layer, the tranche also includes 54 missile warning and tracking satellites. Sandhoo said he expects the first tracking spacecraft to fly soon, within the next few launches.