Orbital ATK’s Cygnus spacecraft is now flying on its own with 3 1/2 tons of experiments, equipment and supplies destined for the crew of the International Space Station.
The Centaur upper stage will continue to burn another minutes to finalize the Cygnus on its orbit. A few minutes later, the Cygnus will separate from the upper stage and pursue the space station on its own.
The single RL-10 engine on the Centaur upper stage continues to burn its hydrogen and oxygen propellants as the stage and attached Cygnus spacecraft continue to pick up speed on their way to orbital velocity. Down range more than 1,600 miles now, the spacecraft and rocket stage just passed 12,000 mph.
The Centaur continues to push the Cygnus spacecraft higher and faster. The two are moving faster than 10,000 mph and are more than 205 miles above the planet. They are more than 1,000 miles downrange of the Florida spaceport.
The launch phase, which is going very smoothly, will take 21 minutes to complete. An hour and half after launch, commands will be given to deploy the Cygnus spacecraft’s UltraFlex solar arrays that will recharge the batteries.
United Launch Alliance reports the Atlas V and Cygnus spacecraft are flying ‘right down the middle” of their course.
The Centaur upper stage has taken over after the first stage burned through its propellants and fell away.
The Atlas V is climbing fast to put Cygnus on its proper orbit. 31 miles, 4,649 mph. The booster will maintain a 3.5-G load on the vehicle during the climb into space.
The Atlas V and Cygnus have broken the sound barrier and are passing through the area of maximum dynamic pressure.