Northrop Grumman Delivers 21 Satellites for Space Development Agency Network
Northrop Grumman has delivered the first 21 satellites of its Tranche 1 Transport Layer batch to Vandenberg Space Force Base in California, where they are being prepared for launch. The spacecraft are part of the Space Development Agency’s Proliferated Warfighter Space Architecture, the low-Earth-orbit network the Pentagon is building for military data transport and missile defense.
The company announced the delivery on September 28. It said several dozen more of its satellites are due to launch into low Earth orbit over the next six months, with dozens already fully integrated and in final checkout.
21 Satellites Ready to Fly
The 21 satellites will carry secure communications and data transport for the warfighter, and they will also relay data for the architecture’s tracking layer, which is aimed at spotting missile threats. Northrop is one of four prime contractors on Tranche 1, alongside York Space Systems, Lockheed Martin and L3Harris.
Northrop puts the total at 150 satellites in its pipeline for the architecture. Lou Christen, the company’s senior director of proliferated systems, said the team has built mission understanding into each phase of development to balance speed against mission utility. Keith Matthews, the Tranche 1 Transport Layer program manager, pointed to the company’s roughly 7 million square feet of space manufacturing floor, which he said is equipped with advanced manufacturing systems and artificial intelligence tools.
Those are the company’s descriptions of its factory operation. The delivery itself is the concrete milestone. The satellites have not yet flown.
A Launch Campaign That Restarted in July
The delivery comes after a difficult stretch for Tranche 1. The Space Development Agency paused launches for nine months after software and hardware problems showed up on the first satellites placed in orbit in October and November 2025, DefenseScoop reported in July. The agency cited mismatches between thermal modeling and on-orbit performance, trouble with electric propulsion that kept some satellites from reaching their planned orbital planes, and ground connectivity issues. One Lockheed Martin satellite lost contact.
SDA Director Gurpartap Sandhoo said at the time that the agency saw issues on the satellites in orbit and paused “to make sure we fix at least the known issues.” He added that he would rather accept a three-week launch delay than a four-month checkout delay.
Launches resumed on July 16, when a SpaceX Falcon 9 carried 21 satellites into orbit. That brought the number in orbit to 63 across three missions. Seven more Tranche 1 launches are planned, three for the transport layer and four for the tracking layer, according to DefenseScoop.
Northrop’s Larger Role in the Network
Tranche 1 is only part of Northrop’s satellite work for SDA. The Space Development Agency awarded the company a $732 million contract in October 2023 to build 38 Tranche 2 Transport Layer Alpha satellites, and Northrop was later selected for Tranche 2 Transport Layer Beta as well. Earlier reporting put the first launch of the Tranche 2 Alpha satellites at December 2026.
The transport layer is meant to work as a mesh network in space, passing targeting and tracking data between sensors and shooters faster than existing links. SDA plans to build the architecture in tranches roughly two years apart, so lessons from Tranche 1 feed directly into later builds.
Northrop has been busy on the defense side elsewhere. This week the company also won an $18.8 million Army contract for a ramjet counter-drone missile.
Northrop has not published launch dates for the 21 satellites now at Vandenberg.
Sources
- Northrop Grumman, “Northrop Grumman Advances Operational Capability for the PWSA With Delivery of 21 Satellites” (September 28, 2026)
- Defence Industry Europe, “Northrop Grumman delivers first 21 of 150 planned satellites” (September 28, 2026)
- DefenseScoop, “SDA resumes satellite launch campaign following months-long pause, tech issues” (July 16, 2026)
- Northrop Grumman and GovConWire, Tranche 2 Transport Layer Alpha award coverage (October 2023)
