Delta IV rocket
Wait right here. (United Launch Alliance file photo)

The next launch attempt of a Delta IV Heavy rocket from Vandenberg Air Force Base remains up in the air pending results of additional testing, United Launch Alliance representatives said Saturday.

On Dec. 28, ULA representatives said the countdown would not occur any earlier than Jan. 6.

ULA never sought permission from the Western Range to launch on that date, however, and no notices to mariners were issued reporting that they had been approved for liftoff. The notices are required because the launch path may affect navigational safety off the coast of the base.

Additionally, SpaceX locked down Jan. 7 as the launch date for a Faclon 9 rocket and the final set of 10 Iridium Next satellites, before announcing the mission had slipped a day. The launch is now planned for 7:48 a.m. Tuesday from South Base.

Vandenberg typically requires time between launches to reconfigure equipment used to monitor just-launched rockets and missiles to ensure they safely remain on their flight paths.

On Saturday, ULA representatives said a new launch date is under review and awaiting the results of additional testing.

“We continue to remedy the technical issues that caused the last scrub of the Delta IV Heavy, and are working with our partners, the National Reconnaissance Office and the U.S. Air Force, to ensure that we fly when it is safe to do so,” said Gary Wentz, ULA vice president of government and commercial programs.

“We understand that this is a high-priority mission for the nation’s war fighters and we take our commitment to safety and mission assurance seriously.”

The Delta IV Heavy first countdown occurred Dec. 7, but assorted technical troubles and unfavorable weather prevented lift off.

During the Dec. 19 countdown, monitors detected abnormal hydrogen concentrations within a booster engine section leading to a scrub and a lengthier delay.

The rocket is scheduled to carry a top-secret national security payload for the National Reconnaissance Office, a Defense Department intelligence agency.

Noozhawk North County editor Janene Scully can be reached at Follow Noozhawk on Twitter: @noozhawk. Connect with Noozhawk on Facebook.

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Janene Scully | Noozhawk North County Editor

Noozhawk North County editor Janene Scully can be reached at