Rachael Joy

Florida Today

Northrop Grumman's investigation into what caused an Omega solid rocket booster's nozzle to break apart during a May test in Utah has concluded, the company told FLORIDA TODAY on Wednesday.

“The nozzle exit cone break up that occurred at motor shut down was caused by a ground test phenomenon that would not have occurred in flight," the company said in a statement. "We have worked closely with the Air Force to study the issue and we are confident the Omega rocket will perform in flight as expected.”

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Northrop Grumman wouldn’t go into further detail on what the ground test phenomenon was but noted the motor did fire for the full planned duration.

The full-scale static test fire tookplace on May 30 at Northrop Grumman’s facility in Promontory, Utah. Producing 2 million pounds of thrust, the solid rocket fired successfully for 2 minutes before the nozzle at the end of the first stage blew apart in different directions.

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A similar test for the second stage was scheduled for this fall but has been pushed to early next year to “incorporate the lessons learned from the first stage test,” a spokesperson said.

The company is still on schedule for the first flight of Omega in 2021, which will be a certification flight launching from Kennedy Space Center. Once certified, the rocket will begin national security missions for the Air Force starting in 2022.

Northrop Grumman is also building the side-mounted solid motors for NASA’s future Space Launch System rocket but doesn’t anticipate any issues with the nozzle for that system.

The nozzle used on the motor for SLS are made of different materials making it “much heavier and far more robust.”

Last October, the Air Force awarded Northrop Grumman $792 million to complete detailed design and verification of Omega.

Contact Rachael Joy at 321-242-3577 or email rjoy@floridatoday.com. Follow her on Twitter @Rachael_Joy.