Rocket Lab warns of narrowing launch window for Neutron rocket

Rocket Lab has reported that the launch window for its Neutron medium-lift rocket is narrowing, with the possibility of the inaugural flight slipping from late 2026 into 2027. In a filing to the U.S. Securities and Exchange Commission, the company stated that while it has reached “significant milestones across the Neutron program,” the exact timing of the debut depends on the results of first-stage qualification and other critical tests.

Production of the Stage 1 tank is currently aligned with a target delivery to the launch pad in the fourth quarter of 2026. The company noted it is balancing the inaugural launch schedule with the goal of entering the Neutron into service as a system capable of full-scale production and high-cadence operations.

Neutron is a 43-meter, liquid methane-fueled vehicle designed for commercial satellite operators and U.S. national security customers. It features a reusable first-stage booster and a unique design where the payload fairing halves remain attached to the booster after separation. Development previously faced a setback when a first-stage fuel tank ruptured during a hydrostatic pressure trial, contributing to the shifted timeline. CEO Peter Beck emphasized that the company's priority is not just reaching the launch pad for the first flight, but ensuring the vehicle is optimized for rapid reusability and frequent operations.