Delta IV Heavy with NROL-15 satellite liftoff at Cape Canaveral

Friday saw the first launch of a Delta IV Heavy with the upgraded Pratt & Whitney Rocketdyne RS-68A main engines.  The Delta IV was lofting the secret spy satellite code named NROL-15 into orbit for the USA National Reconnaissance Office.

The launch was successfully completed by United Launch Alliance and the USAF at 9:15am EDT after two hours of delays due to technical issues that were resolved over 3 halts to the launch sequence.

The Delta IV Heavy is currently the largest and most powerful rocket in service for the United States.  It has a triple core first stage enabling it to lift the heaviest payloads into orbit.  At launch the boosters generate over 2.1 million pounds of thrust.

The launch was scheduled for 6:13am EDT and countdown proceeded normally to the T-4 hold.  Prior to coming out of the T-4 hold all stations were polled and a GO FOR LAUNCH was given.  A minute or so later the countdown resumed and the clocks started running.  This was short-lived though as a there was a voltage spike as the rocket switched to internal power.

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