Final preparations for shuttle launch begin at T-6 Hours with loading the External Tank (ET) with Liquid Hydrogen (LH2), the Space Shuttle Main Engine (SSME) fuel, and Liquid Oxygen (LOX), the SSME oxidizer. Tanking operations are done slowly and with a great deal of care, as these propellants are stored at cryogenic temperatures, LH2 at -423° F, and LOX at -297° F.
TIME |
EVENTS |
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T-06H00M |
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ET Ready For LOX & LH2 Loading |
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Orbiter Ready For LOX &LH2 Loading | |
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Proceed With LOX & LH2 Load | |
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Initiate LOX Transfer Line Chilldown | |
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Initiate LH2 Transfer Line Chilldown | |
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Perform OMS Prop Tank Repressurization | |
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Verify SRB Nozzle Flex Bearing & SRB Nozzle To Case Joint Temperature Requirements | |
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Activate LCC Monitoring Software | |
T-05H50M |
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LH2 Facility & Orbiter Chilldown Complete |
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Initiate LH2 Slow Fill to 5% Sensors Wet LOX Transfer Line Chilldown Complete |
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Initiate Orbiter MPS Chilldown | |
T-05H22M |
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Perform IMU Preflight Calibration |
T-05H20M |
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Orbiter MPS Chilldown Complete Initiate LOX Slow Fill |
T-05H15M |
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LH2 Engine Cut Off Sensors Wet |
T-05H10M |
• |
LOX Transition to Fast
Fill Complete Now in Fast Fill To 98% |
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