2025

2025 · SpaceX

SDA Tranche 1 Transport Layer B

successFalcon 9 Block 5 | SDA Tranche 1 Transport Layer B

Tranche 1 Transport Layer B is one of six missions by the United States Space Force Space Development Agency (SDA) for the Proliferated Warfighter Space Architecture (PWSA) Tranche 1 Transport Layer constellation, which will provide assured, resilient, low-latency military data and connectivity worldwide to the full range of warfighter platforms from Low Earth Orbit satellites. The constellation will be interconnected with Optical Inter-Satellite Links (OISLs) which have significantly increased performance over existing radio frequency crosslinks. It is expected to operate over Ka band, have stereo coverage and be dynamically networked for simpler hand-offs, greater bandwidth and fault tolerance. This launch carries 21 satellites manufactured by York Space Systems.

Overview

Date / time
September 10, 2025 at 02:12 PM UTC
Outcome
success
Launch site
Space Launch Complex 4E
Mission
SDA Tranche 1 Transport Layer B
Mission type
Government/Top Secret
Orbit achieved
Polar Orbit

Payloads deployed · 21