SDA Tranche 1 Transport Layer C

Mission

SDA Tranche 1 Transport Layer C on Falcon 9 Block 5. Wed 15 Oct 2025, 23:06:06 UTC. Reported outcome: Success. Launch site: Space Launch Complex 4E. Source: Launch Library 2.

Tranche 1 Transport Layer C 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 Lockheed Martin.

Mission type

Government/Top Secret

Orbit

Polar Orbit

Rocket file imagery

Launch timeline

Times are relative to liftoff.

1. T-0Thu 16 Oct, 01:06 CEST

   Liftoff

   First upwards movement of the rocket

2. T+1 min 12 sThu 16 Oct, 01:07 CEST

   Max-Q

   Maximum dynamic pressure

3. T+2 min 29 sThu 16 Oct, 01:08 CEST

   MECO

   Cut-off of the main engine

4. T+2 min 33 sThu 16 Oct, 01:08 CEST

   Stage 2 Separation

   Separation of the second stage from the first

5. T+2 min 40 sThu 16 Oct, 01:08 CEST

   SES-1

   First start of the second engine

6. T+3 min 16 sThu 16 Oct, 01:09 CEST

   Fairing Separation

   Separation of the payload fairing

7. T+6 min 33 sThu 16 Oct, 01:12 CEST

   Entry Burn Startup

   Start of the atmospheric entry burn

8. T+6 min 58 sThu 16 Oct, 01:13 CEST

   Entry Burn Shutdown

   End of the atmospheric entry burn

9. T+8 min 17 sThu 16 Oct, 01:14 CEST

   Stage 1 Landing Burn

   Start of the first stage landing burn

10. T+8 min 33 sThu 16 Oct, 01:14 CEST

    SECO-1

    First cut-off of the second engine

11. T+8 min 41 sThu 16 Oct, 01:14 CEST

    Stage 1 Landing

    Landing of the first stage

Slip history

Changes recorded by Space Right Now

No changes since we started tracking on Sat 10 Oct 2026, 11:17 UTC.

Launch pad

Space Launch Complex 4E

Vandenberg SFB, CA, USA (US)

Coordinates: 34.632, -120.611