Rocket Lab has confirmed that its medium-lift Neutron rocket will not make its first flight until 2027. The delay stems from a manufacturing defect in the carbon-composite domes at the ends of the first stage's propellant tanks. Engineers found voids, or air pockets, between layers of carbon fiber in a newly cured forward dome, prompting an investigation and a pause in production. The first stage is the largest pressurized structure ever made from carbon composite, according to CEO Peter Beck, and it required new out-of-autoclave curing processes.
According to Rocket Lab, the voids were linked to a design change introduced after a propellant tank ruptured during a hydrostatic pressure test in January. That earlier failure was blamed on a manufacturing defect at a critical joint in a tank built by a third-party contractor using manual hand-layup. Rocket Lab responded by removing joints and thickening sections of the composite structure—and those thicker sections are where the voids formed.
Rocket Lab says the issue has been resolved by modifying the manufacturing process again; an aft dome made with the updated procedure passed inspection. The company still faces a long checklist before launch, including final qualification of the first stage and the Archimedes engine, followed by a multi-month launch campaign at Wallops Island, Virginia. The two Ars Technica reports are identical in their account, and The Register's coverage agrees on the 2027 slip and the carbon-composite cause, adding the rocket's 'Hungry Hippo' nickname.