Soyuz Countdown Timeline – Kourou

Time Event
L-08:00:00 Soyuz Systems Checks
L-06:00:00 Battery Installation in Booster
L-04:20:00 Sate Commission Meeting
L-04:00:00 Propellant Loading
L-01:45:00 Tanking Complete — LOX Replenish
L-01:45:00 Launcher Systems Checks
L-01:00:00 Guidance System Activation
L-01:00:00 Mobile Service Structure Retraction
L-00:45:00 Flight Computer Software Load
L-00:30:00 Launch Command Power Activation
L-00:10:00 Inertial Guidance System Activation
L-00:10:00 On-Board Recorders activated
L-00:08:00 Payload to Internal Power
L-00:06:00 COUNTDOWN AUTO SEQUENCE
L-00:05:00 Ground & On-Board Telemetry Activation
L-00:05:00 Transfer to onboard Control
L-00:05:00 Launch Key Inserted
L-00:03:15 Engine Nitrogen Purge
L-00:02:40 Umbilical mast power disconnected to 3rd stage
L-00:02:35 Propellant Tank Pressurization
L-00:02:30 Onboard Measurement System Activation
L-00:02:15 Propellant Tank Drain&Safety Valves closed
L-00:02:15 LOX and N2 Loading Termination
L-00:01:00 Transfer to Internal Power
L-00:01:00 AUTO SEQUENCER ENABLED
L-00:01:00 First Umbilical Tower Separates from Booster
L-00:00:40 Power Umbilical to third Stage disconnected
L-00:00:20 ENGINE IGNITION (Core Stage and Boosters)
L-00:00:15 Intermediate Thrust Level
L-00:00:15 Second umbilical Tower separated from Booster
L-00:00:10 Engine Turbopumps at Flight Speed
L-00:00:05 Full Thrust Level
L-00:00:00 Fueling Tower Retracts
L-00:00:00 LIFTOFF