Launch of ULA's new Vulcan Centaur rocket delayed to late 2023

United Launch Alliance (ULA) said it is pushing the launch of its new Vulcan Centaur rocket to later this year following an explosion during recent testing.

During its fifteenth test of the first stage of the two-stage, heavy-lift launch vehicle, the Vulcan ran into a technical issue.

"A hydrogen leak developed somewhere on this stage," explained Tory Bruno, ULA president and CEO.

The leak grew and reached a tipping point four minutes into the test.

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Artist rendering of United Launch Alliance Vulcan Centaur rocket in stages. [Credit: ULA]

"In that window of time, the hydrogen reached a flammable concentration. It found an ignition source, and it caught fire," said Bruno.

ULA has been troubleshooting the rocket for months and discovered two main issues with the space company’s largest rocket.

"Two things together – higher loads, somewhat lower strength in the welds  -- are what caused the crack to begin," Bruno added. "We just simply needed to be a little bit thicker, just 20% thicker."

He said the fix is simple and crews should have everything certified for an end-of-the-year lift-off from Florida's Space Coast.

ULA has had a perfect success rate in its nearly 20-year span of operations and is optimistic this new technology will not break that streak.