On Eve Of Launch Return, SDA Mesh Network Remains Work In Progress

As the U.S. Space Force’s Space Development Agency prepares for the third launch of its proliferated data relay network as early as July 16, it still has work to do before the satellites on orbit can be considered a working “mesh network,” Director Gurpartap Sandhoo said July 14.

“We have not established a mesh [network] yet, but we are working our way toward it,” he said in a virtual media roundtable.

In 2025, the SDA launched 42 satellites to low Earth orbit (LEO) across two missions to start operationalizing the new proliferated constellation known as the Transport Layer. But it hit snags during the on-orbit test and checkout period that prompted a nine-month pause in what were originally intended to be monthly deployments.

Following the inaugural launch of 21 satellites built by York Space Systems, the team discovered several hardware and software issues with the satellites on orbit, including discrepancies in initial thermal models that required “additional thermal mitigation,” he told reporters. As of May 11, Sandhoo is dual-hatted as the SDA director and the Space Force’s portfolio acquisition executive for missile warning and tracking.

York also had to install additional ground entry points to ensure the satellites could sufficiently connect with its Earth-based network. SDA was hoping to achieve five passes per day and ended up with about 3.5 passes per day. “We’re trying to make sure we don’t have that same challenge again,” Sandhoo said.

SDA has also run into orbit-raising issues. One of the 21 Lockheed Martin-built satellites that was launched last October has been out of contact “for quite some time now,” Sandhoo said. Other satellites did not make it to the correct orbital plane following propulsion issues, he added.

Now that they have burned through some of those hard rocks, the agency is ready to resume those launches—but not necessarily at that monthly rate. “I’m not trying to give an artificial timeline,” Sandhoo said, noting that on-orbit checkout remains ongoing for the Tranche 1 birds that have already launched. “The goal is to launch and get quickly through the checkout, so we can get to operations,” he added, saying he would take a three-week launch delay to avoid a four-month delay to complete on-orbit checkout. “That’s the kind of math we’re doing.”

The next launch is set for July 16 from Vandenberg SFB, California, and will be supported by SpaceX with a dedicated Falcon 9 launch vehicle. It will carry the second batch of York-built Transport Layer satellites awarded in 2022 under the SDA’s Tranche 1 contract.

The full Tranche 1 Transport Layer will include more than 150 satellites built by York Space Systems, Lockheed Martin and Northrop Grumman, meant to provide Link 16, Ka-band and optical communications to the Joint Force and data relay for other space-based missions including missile warning/missile tracking. To move quickly, the SDA is processing any plane of satellites that is ready to go in the launch queue. York’s second plane was the fastest, and so it is going up next, Sandhoo said.

That also means some satellites procured under Tranche 2—which were awarded in 2023-24 and targeted for launch beginning in fiscal 2027—could go up before all the Tranche 1 satellites are launched. “If they are ready to go, we will process them and we’ll get them to orbit,” Sandhoo said.

He expressed optimism that the Tranche 1 Transport Layer could begin paying dividends to the Joint Force soon. “By the end of this launch, we’ll have half of our Transport constellation on orbit,” he said. “Once you have three planes up, we’re starting to talk real capability for the warfighter.” SDA is targeting three additional missions supporting the Tranche 1 Transport Layer, and four launches for the Tranche 1 Tracking Layer, Sandhoo said.