LONG BEACH, USA, Oct. 14, 2026 - Rocket Lab has delayed the maiden launch of its Neutron rocket from the fourth quarter of 2026 to no earlier than 2027,^[1][2] disclosing the slip in a Form 8-K filed with the SEC on 14 October.^[3] Inspections found voids in a newly cured carbon-composite forward propellant dome for the first stage.^[4] It is not the first delay. Neutron was unveiled in 2021 with a 2024 launch target,^[5] and in November 2025 the company moved its debut from late 2025 to the first quarter of 2026.^[6] Rocket Lab says it has added manufacturing fixes to prevent new voids,^[7] that a new dome will be built and inspected before the first quarter,^[8] and that three steps remain before it sets a precise launch date.^[9] The second and third Neutron rockets are already being built.^[10] Neutron is Rocket Lab's reusable medium-class launch vehicle.^[11] Carbon fibre has flown successfully on small rockets such as Rocket Lab's Electron and Firefly's Alpha, but is untested at medium-lift scale.^[12] Rocket Lab shares fell 8% to $59.18 on the day of the announcement.^[13] Space Nugget. Carbon fibre composites are used in rocket structures because they are far lighter than metal alloys for the same strength, and every kilogram saved on the structure can be carried as payload. The trade-off is that composites are hard to build without hidden flaws, such as voids where the layers fail to bond, which is why large tanks are inspected so closely.