Shuttle Mission STS-104
Orbiter - Atlantis
July 12, 2001

 

L-3 Thru L-1 Countdown Events Summary

 

Did You Know?

The flight crew arrived at Kennedy Space Center on Sunday, July 8th at 9:30 p.m. EDT
 

"L" stands for Launch, "-" stands for minus, "3" stands for days

L-3
Event Description
Date
Eastern Daylight Saving Time
è The countdown gets underway with the traditional call to stations by the NASA Test Director. This verifies that the Launch Team is in place and ready to proceed.

July 9 , 2001
7:30 A.M.

è Countdown clock begins at the T-43 hour mark ( 8:00 a.m.).
è Begin final vehicle and facility close-outs for launch.
è Remove mid-deck and flight-deck platforms ( 4:00 p.m.)
è Activate and test navigational systems ( 9:00 p.m.)
è Complete preparation to load power reactant storage and distribution systems ( 11:00 p.m.)
L-2
Event Description
Date
Eastern Daylight Saving Time
è Complete flight deck preliminsary inspections.

July 10, 2001
12:01 A.M.

è Enter first built-in hold at T-27 hours for a duration of 4 hours.

11:00 A.M.

è Clear launch pad of all non-essential personnel.
è Begin operations to load cryogenic reactants into Atlantis' fuel cell storage tanks ( 5:30 a.m. - 10:30 a.m.).
è Enter built-in hold at T-19 hours for a duration of 4 hours.

12:00 P.M.

è Demate orbiter mid-body umbilical unit ( 12:30 p.m.)
è Resume countdown at T-19 hours and counting ( 4:00 p.m.)
è Final preparations of the Shuttle's three main engines for main propellant tanking and flight.
è Begin filling pad sound suppression systems water tank ( 5:30 p.m.) complete ( 10:30 p.m.).
è Resume orbiter and ground support equipment close-outs.
è Close out the tail service masts on the mobile launcher platform.
 

Did You Know?

At launch minus 11 hours a planned countdown hold -- called a built-in hold -- begins.  This hold period can last for up to 26 hours, 16 minutes depending on the type of payload, tests required and other factors. This time is also used, if needed, to perform tasks in the countdown that may not have been completed earlier.
L-1
Event Description
Date
Eastern Daylight Saving Time
è Enter planned hold at T-11 hours for 13 hours, and 15 minutes.

July 11 , 2001
12:01 A.M.

è Begin star tracker functional checks ( 1:00 a.m.)
è Activate orbiter's inertial measurement units.
è Activate the orbiter's communications systems.
è Move Rotating Service Structure (RSS) to the park position ( 9:00 a.m.).
è Perform ascent switch list.
è Fuel cell flow-through purge complete.

è

Resume countdown at T-11 hours and counting.

1:08 P.M.

è Activate the orbiter's fuel cells ( 2:18 p.m.)
è Clear the blast danger area of all non-essential personnel.
è Switch Atlantis' purge air to gaseous nitrogen. ( 3:23 p.m.)
L-0
Event Description
Date
Eastern Daylight Saving Time
è Resume countdown at T-3 hours

July 12, 2001
1:08 A.M.

è Crew departs Operations & Checkout Building for the launch pad ( 1:13 A.M.)


* Other events will be covered during our online coverage beginning at T-6 hours and counting. *