Tranche 1 Transport Layer B

Launch Success

Liftoff Time (GMT)

14:12:11

Wednesday September 10, 2025

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Mission Details

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Tranche 1 Transport Layer B

(T1TL-B)

Wiki

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.

Manufacturer: York Space Systems

Operator: Space Development Agency

Polar Orbit

21 Payloads

Rocket

Active
Falcon 9 Block 5

Active Since 2018

SpaceX logo

Agency

SpaceX

Price

$69.75 million

Rocket

Diameter: 3.7m

Height: 70m

Payload to Orbit

LEO: 22,800 kg

GTO: 8,300 kg

Liftoff Thrust

7,607 Kilonewtons

Fairing

Diameter: 5.2m

Height: 13m

Stages

2

Launch Site

General Trajectory

SE

SW

Launching

South

SLC-4E

Vandenberg SFB, California, USA

Fastest Turnaround

2 days 21 hours

Stats

Falcon 9


531st

Mission

113th

Mission of 2025

SpaceX


557th

Mission

117th

Mission of 2025

2025


208th

Orbital launch attempt