Delta IV Heavy scrubs again, ULA chief vows to change readiness operations

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  The Mobile Service Tower rolls back from the United Launch Alliance Delta IV Heavy rocket carrying the NROL-44 mission on Wednesday, September 30. [credit: United Launch Alliance ]

Late on Wednesday night, United Launch Alliance's large Delta IV Heavy rocket again came within seconds of lifting off from its Florida launch pad. But once again, the launch was scrubbed.

Following the automated abort of the rocket at T-7 seconds, both the booster and its valuable National Reconnaissance Office payload were said to be safe. Because the abort was triggered just before the rocket's main RS-68 engines had begun to ignite, the delay before the next launch attempt may be less than a week.

"The terminal countdown sequencer rack identified an unexpected condition prior to the engine start sequence," the company stated about an hour after the scrub. "The TCSR, which controls the final 10 seconds of the countdown, performed as intended and safely initiated a hold at T-7 seconds. The team is currently reviewing all data and will determine the path forward."