Rocket Lab Archimedes Engine Tests: Explosion & Neutron Rocket Delay?
- Rocket Lab is navigating a series of engine test anomalies as it prepares to launch its new Neutron rocket, a medium-lift launch vehicle intended to significantly expand the...
- The Archimedes engine, powered by liquid oxygen and methane, is central to the Neutron rocket’s design.
- The incident at Stennis Space Center, occurring on November 30, 2025, initially reported as a grass fire triggered by an electrical box malfunction, appears to have been far...
Rocket Lab is navigating a series of engine test anomalies as it prepares to launch its new Neutron rocket, a medium-lift launch vehicle intended to significantly expand the company’s capabilities. While the company downplays the incidents as a normal part of the development process, reports indicate at least two Archimedes engine tests have failed in the last three months, including one resulting in substantial infrastructure damage at the Stennis Space Center in Mississippi.
The Archimedes engine, powered by liquid oxygen and methane, is central to the Neutron rocket’s design. Nine of these engines will be clustered to provide a sea-level thrust of 165,000 pounds. The engine’s development is now a critical path item for Neutron’s debut, which Rocket Lab is still aiming for later this year, despite a shifting timeline that has seen initial launch targets pushed back from 2024 to 2025, and now to .
The incident at Stennis Space Center, occurring on , initially reported as a grass fire triggered by an electrical box malfunction, appears to have been far more serious. According to a source with direct knowledge of the event, the characterization of an “electrical fire” is inaccurate. Satellite imagery confirms significant damage to the A3 test stand, with the roof blown off one of the two test cells. The source described the event as a “catastrophic engine explosion” that caused “significant infrastructure damage.”
Rocket Lab CEO Pete Beck, responding to inquiries about the anomalies, characterized the tests as pushing the engines to their limits, stating, “We test to the limits, that’s part of developing a successful rocket. We often put the engine into very off nominal states to find the limits and sometimes they let go, this is normal and how you ensure rockets don’t fail in flight.” This perspective frames the failures as expected occurrences in a rigorous testing regime, designed to identify and address potential weaknesses before flight.
The Neutron rocket represents a significant leap for Rocket Lab, which has primarily focused on the smaller Electron rocket. Neutron is designed to be partially reusable, aiming to lower launch costs and increase launch cadence. The rocket is intended to compete in the medium-lift launch market, currently dominated by SpaceX’s Falcon 9 and other established players. The development of Neutron has involved substantial investment in new infrastructure, including a production facility and launch complex at Wallops Island, Virginia, with construction beginning in .
The timeline for Neutron’s development has been subject to revisions. Initially announced in , with early projections for a 2024 launch, the target gradually shifted to 2025. Throughout 2023, the company maintained a publicly stated target of 2024-2025, but by early 2024, discussions began to indicate a potential slip to late 2025 or early . Official timelines published in early-to-mid 2024 continued to list 2025 as the target, before the recent fuel tank rupture reported on , which has further delayed the debut to .
The recent fuel tank rupture, coupled with the engine test failures, raises questions about the program’s schedule and technical challenges. While Beck’s comments suggest the company is prepared for such setbacks, the extent of the infrastructure damage at Stennis and the need to address the root causes of the engine failures could introduce further delays. The Archimedes engine’s development is particularly crucial, as it represents a new design for Rocket Lab, moving beyond the proven kerosene-fueled Rutherford engines used on the Electron rocket.
The use of liquid oxygen and methane as propellants offers several advantages, including higher performance and cleaner burning compared to kerosene. However, methane engines also present unique engineering challenges, particularly in achieving reliable ignition and combustion stability. The recent anomalies suggest that Rocket Lab is still working through these challenges as it strives to finalize the Archimedes engine’s design and prepare it for flight.
The delays and setbacks with Neutron come at a time of increasing competition in the launch market. SpaceX continues to dominate the industry with its Falcon 9 and Starship rockets, while other companies, such as Blue Origin and Relativity Space, are also developing new launch vehicles. Rocket Lab’s ability to successfully bring Neutron online will be critical to its long-term growth and its ability to compete in the expanding space economy.