Rocket Lab has successfully completed qualification testing of the “Hungry Hippo” — the head fairing of the new Neutron rocket. Its first launch is scheduled for early 2026.
We've completed qualification & acceptance testing of the Hungry Hippo fairing for Neutron ? With the design, structure, and operations of Neutron's fixed reusable fairing and upper module now proven out, Hungry Hippo is ready for launch. pic.twitter.com/8I0DKE4Ugt
— Rocket Lab (@RocketLab) December 8, 2025
Hungry Hippo in space
The Neutron rocket project was first announced by Rocket Lab in 2021. It is a partially reusable medium-class launch vehicle capable of delivering up to 13 tons of payload to low Earth orbit in a configuration with first-stage recovery. The rocket has an innovative design, the main feature of which is that during launch, the second stage will be “hidden” inside the first stage, equipped with an deployable head fairing.
The idea is that upon reaching the desired stage of flight, the first stage of Neutron will open the fairing, like a giant mouth, and release the second stage with the payload. After that, the first stage will close again and return to Earth, while the second stage will activate its engine and deliver the payload to the desired orbit. A modified 120-meter Return On Investment barge will be used to land the first stage.
Thanks to this approach, Rocket Lab will simultaneously return both the first stage and the fairing. SpaceX also returns the Falcon 9 fairing, but using a different principle: its halves separate and fall to Earth independently of each other and the first stage, after which they are picked up by ships.
Neutron testing
Before launching Neutron into space, Rocket Lab conducted a series of intensive tests on its head fairing. These included:
- Exposure to an external force of 1223 kN to simulate dynamic pressure during launch;
- Checks of the opening and closing cycle of mechanisms to ensure faster-than-required operation;
- Software integration;
- Loads exceeding design requirements by 125%.
The fairing will now be delivered to the Mid-Atlantic Regional Spaceport (MARS), located on Wallops Island off the coast of Virginia. Rocket Lab has its own launch pad there.
Upon arrival at the spaceport, Hungry Hippo will be integrated into the Neutron first stage for pre-launch testing, including static tests and a launch rehearsal. Rocket Lab plans to conduct the first launch of the new rocket early next year.
