







Falcon 9 countdown timeline

SPACEFLIGHT NOW

Posted: September 28, 2013



NOTE: All times approximate T-minus 13 hours, 30 minutes Power Vehicle Launch controllers power up the Falcon 9 rocket for countdown operations. T-minus 13 hours Cassiope Status Report The Cassiope mission manager provides the "go" for launch. T-minus 3 hours, 50 minutes Begin LOX Loading Liquid oxygen begins flowing into the Falcon 9 rocket's first and second stages. T-minus 3 hours, 40 minutes Begin RP-1 Loading Highly-refined kerosene - a product called RP-1 - begins flowing into the Falcon 9 rocket's first and second stages. T-minus 3 hours, 15 minutes Fueling Complete The Falcon 9's propellant tanks are full. Cryogenic liquid oxygen will continue to be replenished until the final minutes of the countdown. T-minus 13 minutes Final Readiness Poll The launch team is polled for their "go" or "no go" for entering the terminal countdown. T-minus 6 minutes Align Flight Computer The Falcon 9's flight computer is aligned for flight. T-minus 6 minutes Start Terminal Count Autosequence The computer-controlled automatic countdown sequencer starts. T-minus 5 minutes Falcon Internal Power The Falcon 9 rocket is transitioned to internal power. T-minus 3 minutes Terminate LOX Loading The liquid oxygen replenishment to the rocket's first and second stages ends and the system is readied for liftoff. T-minus 2 minutes SpaceX Reports GO The SpaceX launch director confirms the Falcon 9 is "go" for launch. T-minus 2 minutes Air Force Range Reports GO The U.S. Air Force range safety officer verifies "go" for launch. T-minus 1 minute Flight Computer in Start-Up Mode The Falcon 9 flight computer is commanded to start-up mode, and the launch pad's Niagara and deck water systems are activated. T-minus 50 seconds First Stage Steering Check The thrust vector control, or gimbal, system on the first stage's Merlin 1D engines is checked for launch. T-minus 40 seconds Pressurize Propellant Tanks The Falcon 9's first and second stage propellant tanks are pressurized for flight. T-minus 3 seconds Start Engine Ignition Sequence The engine controller commands the Falcon 9's nine Merlin 1D first stage engines to ignite, followed by a computer health check to verify the engines are healthy before liftoff.

Data source: SpaceX

