7:29 p.m. - The countdown is at T-9 minutes and counting. As the count resumes, the GLS will be in control of all critical space shuttle launch operations and there are several milestones before launch at 7:38. They include:
At T-16 seconds, the launch pad’s water sound suppression system begins flooding the mobile launcher platform with 300,000 gallons of water. The system protects the shuttle and its payload from any damage caused by energy generated during launch.
At T-10 seconds, flares ignite under Atlantis’ three main engines to burn away any residual hydrogen that may have collected near the main engine nozzles.
At T-6.6 seconds, the main engines will begin firing in anticipation of liftoff.
7:28 p.m. - The orbiter’s “black boxes” are now in the recording mode and will continue to collect data about the performance of the shuttle systems during the flight.
7:24 p.m. - Launch Director Mike Leinbach is performing the poll to determine a “go/no-go” for launch. The team is a go! He wished the Atlantis crew members good luck and Godspeed.
7:14 p.m. - The countdown clock is holding at T-9 minutes. The final prelaunch polls soon will be taking place.
T - 90 seconds
Sound wave hit us at about 4:05 after launch and rattled the windows, this far away!