First stage engines continue to fire. Proton is approaching maximum dynamic pressure of about 800 pounds per square foot. Altitude is 6 km. All systems reported to be operating normally. The Proton rocket has made its roll maneuver to achieve the proper launch heading.
Rocket is stable as it blasted into the night sky.
Liftoff of the Proton rocket, completing the Sirius Satellite Radio constellation with the third digital audio broadcasting spacecraft. T-minus 1 minute. The engine start command will be issued by the launch sequencer at T-minus 2.5 seconds. The six first stage engines will be ignited at T-minus 1.6 seconds and commanded to 40 percent thrust. The thrust level is then increased to 100 percent at T-0 seconds.