Firing chain is arm, sound suppression, water system activated. D-13, 12, 11, 10, 9, 8, go for the main engine start. Six, five, four, three, two, one, and zero and liftoff of spatial and lens. We should be dressed of its historic achievements in space. Hacking, the Atlantic, the D-Roll. Roger rolling. Houston is now controlling. The roll maneuver is completed. Lannis is in a head-stab position on course for a 51.6 degree, 136 by 36 statue mile orbit. At the three main engines on Atlantic have now been throttled down to 72% of rated thrust as the orbiter prepares to pass through the area of maximum dynamic pressure on the vehicle in the lower atmosphere. The engines now begin to throttle back up. Atlantic, you are go at throttled up. Got to go. I try to up. All three engines looking really good back at full throttle now. It lift off the fully fueled shuttle boosters and external tank, weighed 4.5 million pounds. It now is burned half of that lift off weight and propellant. One minute 30 seconds into the flight. All three auxiliary power units that provide hydraulic power to the orbiter's systems in good shape as are the fuel cells providing electricity to all of the systems on board. Atlantic is already 19 miles in altitude, down-race from the Kennedy Space Center, 20 miles traveling, 2,500 miles per hour. Coming up on staging the point at which the twin solid rocket boosters burn out and separate from the orbiter. Booster separation confirmed?