Rocket Lab completed a full-duration burn of its Archimedes engine at NASA's Stennis Space Center in Mississippi, marking a critical qualification test for the engine that will power the company's next-generation Neutron launch vehicle. The test lasted just under 5.5 minutes and simulated flight-like conditions, clearing a major hurdle before Neutron's first stage integration. This progress comes as Rocket Lab continues regular Electron launches while pushing toward Neutron's debut, though the company has shifted its target to the first half of 2026 after encountering setbacks including a main stage tank rupture during pressure testing in January.
Neutron's first stage will carry eight Archimedes engines producing nearly 1.5 million pounds of combined thrust at liftoff, with each engine's output comparable to SpaceX's Falcon 9 Merlin engines. The first stage is designed for reusability, capable of returning to the launch site or a droneship. The second stage uses a single vacuum-optimized Archimedes variant with an extended nozzle that produces 20 percent more thrust in vacuum. Neutron's payload fairings employ a unique "Hungry Hippo" design where halves separate like a clam shell, allowing the second stage to emerge and provide final orbital insertion.