TRACERS

Mission

TRACERS on Falcon 9 Block 5. Wed 23 Jul 2025, 18:13 UTC. Reported outcome: Success. Launch site: Space Launch Complex 4E. Source: Launch Library 2.

NASA's Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites (TRACERS) mission, consisting of two identical satellites that will orbit Earth in tandem (one following the other), will help understand magnetic re-connection and its effects in Earth’s atmosphere. Magnetic re-connection occurs when activity from the Sun interacts with Earth’s magnetic field. By understanding this process, scientists will be able to better understand and prepare for impacts of solar activity on Earth. Hitchhiking small satellites: * Athena EPIC (Economical Payload Integration Cost) * Polylingual Experimental Terminal (PExT) * Relativistic Electron Atmospheric Loss (REAL)

Mission type

Heliophysics

Orbit

Sun-Synchronous Orbit

Launch timeline

Times are relative to liftoff. Clock times are not shown while T-0 is unconfirmed or on hold.

1. T-38 min

   GO for Prop Load

   Launch director verifies go for propellant load

2. T-35 min

   Stage 1 LOX Load

   Start of liquid oxygen loading in the first stage

3. T-35 min

   Prop Load

   Start of propelland loading

4. T-16 min

   Stage 2 LOX Load

   Start of liquid oxygen loading in the second stage

5. T-7 min

   Engine Chill

   Start of engine chilling

6. T-1 min

   Startup

   The onboard computer takes control over the countdown and runs last checks

7. T-1 min

   Tank Press

   Fuel tanks are pressurized to flight levels

8. T-45 s

   GO for Launch

   Launch director verifies go for launch

9. T-3 s

   Ignition

   Start of the engine ignition sequence

10. T-0

    Liftoff

    First upwards movement of the rocket

11. T+1 min 12 s

    Max-Q

    Maximum dynamic pressure

12. T+2 min 13 s

    MECO

    Cut-off of the main engine

13. T+2 min 17 s

    Stage 2 Separation

    Separation of the second stage from the first

14. T+2 min 21 s

    Stage 1 Flip

    Flip maneuver of the first stage

15. T+2 min 24 s

    SES-1

    First start of the second engine

16. T+2 min 30 s

    Booster Boostback Burn Startup

    Start of the booster boostback burn

17. T+2 min 56 s

    Fairing Separation

    Separation of the payload fairing

18. T+3 min 26 s

    Booster Boostback Burn Shutdown

    End of the booster boostback burn

19. T+6 min 4 s

    Entry Burn Startup

    Start of the atmospheric entry burn

20. T+6 min 21 s

    Entry Burn Shutdown

    End of the atmospheric entry burn

21. T+7 min 12 s

    Stage 1 Landing Burn

    Start of the first stage landing burn

22. T+7 min 46 s

    Stage 1 Landing

    Landing of the first stage

23. T+8 min 2 s

    SECO-1

    First cut-off of the second engine

24. T+50 min 44 s

    SES-2

    Second start of the second engine

25. T+50 min 47 s

    SECO-2

    Second cut-off of the second engine

26. T+54 min 30 s

    Payload Separation

    Final deployment of the payload from the rocket

27. T+54 min 50 s

    Payload Separation

    Final deployment of the payload from the rocket

28. T+1 h 5 min 40 s

    SES-3

    Third start of the second engine

29. T+1 h 5 min 41 s

    SECO-3

    Third cut-off of the second engine

30. T+1 h 30 min 7 s

    SES-4

    Fourth start of the second engine

31. T+1 h 30 min 8 s

    SECO-4

    Fourth cut-off of the second engine

32. T+1 h 34 min 26 s

    Payload Separation

    Final deployment of the payload from the rocket

33. T+1 h 40 min 41 s

    Payload Separation

    Final deployment of the payload from the rocket

34. T+1 h 44 min 46 s

    Payload Separation

    Final deployment of the payload from the rocket

35. T+1 h 45 min 6 s

    Payload Separation

    Final deployment of the payload from the rocket

36. T+1 h 45 min 26 s

    Payload Separation

    Final deployment of the payload from the rocket

Slip history

Changes recorded by Space Right Now

No changes since we started tracking on Sat 10 Oct 2026, 11:16 UTC.

Launch pad

Space Launch Complex 4E

Vandenberg SFB, CA, USA (US)

Coordinates: 34.632, -120.611