Space & Technology — 2026-07-18

Space Development Agency Resumes Tranche 1 Launches With 21 Military Data Transport Satellites After Nine-Month Pause

BLUFSDA's pivot to readiness-based scheduling makes at least one more Tranche 1 launch likely by end of 2026 but compresses the margin for Tranche 2 overlap starting in fiscal 2027.

The Space Development Agency launched its third Tranche 1 batch on Thursday, sending 21 York Space Systems data transport satellites to orbit aboard a SpaceX Falcon 9 from Vandenberg Space Force Base, bringing total on-orbit Tranche 1 vehicles to 63 1. The mission ended a nine-month pause SDA Director Gurpartap Sandhoo attributed to software and hardware issues found on the 42 satellites launched in October and November, including thermal-modeling discrepancies and insufficient ground entry points that slowed checkout 2. Sandhoo told reporters on Tuesday that fixes have addressed most known issues and that the agency will prioritize satellite readiness over a fixed launch cadence 23. SDA has seven more Tranche 1 missions planned, three more transport-layer and four tracking-layer, toward a constellation of 158 total platforms, and expects overlap with Tranche 2 launches beginning in fiscal 2027 23.

Analysis
SDA's shift to readiness-based sequencing signals durable schedule risk across the remaining Tranche 1 manifest, not resolution of a one-off glitch. SDA will likely conduct at least one more Tranche 1 launch by the end of 2026, as contractors clear the backlog of vehicles held by thermal-mitigation retrofits and expanded ground-entry connectivity. High confidence in this judgment rests on Sandhoo's itemized account of resolved defects and the agency's stated seven-mission remaining manifest against a fixed 158-satellite target. Overlap with Tranche 2 launches beginning fiscal 2027 compresses the margin for further slippage, raising pressure on SSC's launch integration pipeline and York's production line.
4 sources
  1. Space Development Agency Successfully Completes Third Launch of Tranche 1 Satellites
  2. SDA resumes satellite launch campaign following months-long pause, tech issues - DefenseScoop
  3. Space Development Agency Launches 21 Data Transport Satellites on SpaceX Rocket - Air & Space Forces Magazine
  4. SpaceX launches 21 satellites for military data network - SpaceNews

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