T-minus 26 hours |
Power Dragon Vehicle |
Launch controllers power up the Dragon spacecraft for countdown operations. |
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T-minus 10 hours |
Power Falcon 9 Vehicle |
Launch controllers power up the Falcon 9 rocket for countdown operations. |
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T-minus 4 hours |
Begin RP-1 Loading |
Highly-refined kerosene - a product called RP-1 - begins flowing into the Falcon 9 rocket's first and second stages. |
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T-minus 3 hours, 20 minutes |
Begin LOX Loading |
Liquid oxygen begins flowing into the Falcon 9 rocket's first and second stages. |
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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. |
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T-minus 13 minutes |
Final Readiness Poll |
The launch team is polled for their "go" or "no go" for entering the terminal countdown. |
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T-minus 10 minutes |
Terminal Countdown Autosequence Start |
The computer-controlled terminal countdown automatic sequence begins at T-minus 10 minutes. |
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T-minus 9 minutes |
Begin Merlin Engine Chilldown |
Pre-valves open to allow super-cold liquid oxygen to flow into the Falcon 9's nine first stage Merlin 1D engines to condition the engine turbopumps for ignition. |
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T-minus 8 minutes |
Dragon Internal Power |
The Dragon spacecraft is transitioned to internal power. |
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T-minus 6 minutes |
Initiate Dragon Autosequence |
The Dragon spacecraft's terminal countdown automatic sequence is started. |
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T-minus 6 minutes |
Align Flight Computer/Internal Power |
The Falcon 9's flight computer is aligned for flight, and the rocket is transitioned to internal power supplies. |
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T-minus 3 minutes |
Terminate LOX Loading/FTS Internal Power |
The liquid oxygen replenishment to the rocket's first and second stages ends and the system is readied for liftoff. And the rocket's flight termination system is switched to internal power. |
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T-minus 2 minutes |
SpaceX Reports GO |
The SpaceX launch director confirms the Falcon 9 is "go" for launch. |
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T-minus 2 minutes |
Air Force Range Reports GO |
The U.S. Air Force range safety officer verifies "go" for launch. |
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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. |
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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. |
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T-minus 40 seconds |
Pressurize Propellant Tanks |
The Falcon 9's first and second stage propellant tanks are pressurized for flight. |
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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. |
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