Rocket Lab shifted Neutron’s first-launch target from the fourth quarter of 2026 to 2027 on October 14, after a manufacturing issue in the first-stage forward propellant dome. Yahoo Finance reported the target change, while Stephen Clark’s report for Ars Technica traced the issue to voids between carbon-fiber layers in thicker dome sections. Clark reported on October 15 that a separate aft dome made with a revised process had passed inspection, while a replacement forward dome still had to be manufactured.
Why the forward dome delayed Neutron
A tank ruptured during hydrostatic pressure testing in January. The test pressurizes a tank with liquid to check its strength. Clark reported that a later design change aimed to strengthen the structure, adding thicker sections to the domes; Rocket Lab CEO Peter Beck said those thicker sections were where the voids formed.
Beck said the large composite domes required custom cure cycles and an out-of-autoclave manufacturing process. An autoclave is a heated pressure vessel used to cure composite parts. Voids are air pockets between layers of carbon fiber, and they appeared in the thicker sections of the forward propellant dome.
Beck said the voids did not necessarily mean a dome would fail in flight, but Rocket Lab wanted appropriate safety margins before proceeding. The investigation and manufacturing work contributed to the revised launch target.
What passed inspection—and what still needed work
The inspection pass applied to an aft dome made with the revised process. In his October 15 report, Clark said Rocket Lab still needed to manufacture a replacement forward dome. The two results concern separate parts of the first-stage propellant tanks.
Yahoo Finance reported that Rocket Lab expected first-stage assembly to finish within the quarter and would then be better positioned to set a launch date. The company’s stated target was 2027.
Qualification and launch preparations
In his October 15 account, Clark reported that final first-stage qualification and qualification of the nine methane-fueled Archimedes engines remained pending. He described the later launch campaign as including integrated fueling tests, countdown rehearsals and a static fire. Such campaigns for a new rocket can take months.
