STS-135 – Final Launch Of The Space Shuttle Program. Atlantis traveling 12,000 miles an hour. The main engines will soon be throttling down once again to limit the stress on the shuttle and it’s four crew members to that of 3 times the effective gravity. Atlantis traveling currently at a speed of more than 4 miles a second. 1 minute of powered flight remaining for Atlantis. 3 good main engines, 3 good auxiliary power units, 3 good fuel cells. Approaching the 8 minute mark into the flight. Atlantis now traveling more than 15,000 miles an hour. 8 minutes and 15 seconds into the flight, standing by for main engine cut off. That will be followed a few seconds later by the separation of the external fuel tank. Complete Full Transcript, Dialogue, Remarks, Saying, Quotes, Words And Text.