Continued fallout from the explosion of the Centaur upper stage on ULA's test stand as Vulcan's launch continues to slip.

In a statement, ULA described the work needed on the Centaur V upper stage as “minor reinforcement at the top of the forward dome,” or the uppermost section of the liquid hydrogen tank. The changes will add strength to the tank, which contains super-flammable fuel chilled to minus 423° Fahrenheit (minus 253° Celsius).

The pressure is on as the DOD is eagerly waiting for Vulcan.

The US Space Force is eager for the Vulcan rocket to enter service. The Pentagon selected ULA and SpaceX in 2020 to launch around 40 of the military’s most critical surveillance, communications, and navigation satellites from 2022 through 2028. ULA won the rights to launch about 60 percent of the missions, primarily using the new Vulcan rocket, with SpaceX taking the remaining 40 percent with its Falcon rocket family.