Sandhoo identified several issues with the first Tranche 1 satellites during a roundtable with reporters before this week’s launch. Ground controllers lacked sufficient ground station coverage to communicate with the satellites after last year’s launches. Some of the satellites encountered thermal control and propulsion system problems as they climbed from their insertion orbit to an operational altitude of more than 600 miles (1,000 kilometers), significantly higher than SpaceX’s Starlink Internet network, Sandhoo said.

“We are in a pretty harsh radiation environment at 1,000 kilometers, so not all of our orbit raising has gone according to plan,” he said. “It has been sporadic. We’re working through it.” Sandhoo is optimistic that ground teams will eventually declare most of the satellites ready for operations, but it’s taking longer than expected.

Getting it right

SDA and its contractors “took a pause” after last year’s launches to “make sure we fixed at least the known issues,” Sandhoo said. “We expect this launch to be a lot smoother than the last one.”

Thursday’s launch was the second SDA launch of York’s data transport satellites, and the third for Tranche 1 overall. Seven more launches will complete Tranche with 63 additional data transport satellites and 28 missile tracking satellites manufactured by Lockheed Martin, Northrop Grumman, and L3Harris. None of the Tranche 1 tracking satellites have launched yet.

Sandhoo said the schedule for the next series of SDA satellites is “still constrained” by the availability of optical communication terminals, the laser transmitters and receivers needed to connect the transport and tracking satellites into one integrated mesh network.

While SDA officials declined to say when the next few launches might occur, the agency said the Tranche 1 satellites will “provide initial warfighting capability beginning in 2027. Sandhoo said the agency is no longer focused on achieving a monthly launch cadence. It’s more important, he said, to make sure SDA’s satellites launch when they are ready. “The goal is to get operational as quickly as possible once you get in orbit,” he said.