RKLB Stock Rises Overnight: Rocket Lab Completes Major Engine Test Ahead of Neutron’s First Launch

• The company completed a full-duration burn of Neutron’s second-stage AVac engine.
• Rocket Lab called the test “a thing of beauty” and said it was critical for Neutron’s first flight.
• The firm recently completed the Space Force’s Victus Haze mission ahead of key deadlines.

Shares of Rocket Lab (RKLB) rose 1% overnight late Monday after the company completed a full-duration burn of Neutron’s second-stage engine, clearing another key milestone ahead of the rocket’s first launch.

RKLB stock declined 5% on Monday, logging its sixth consecutive session in the red. 

RKLB Completes Key Neutron Engine Test 

Rocket Lab said its Archimedes Vacuum (AVac) engine completed a full-duration burn, calling the test “a thing of beauty” on X. The engine produces about 1.2 times the thrust of the first-stage Archimedes variant and is 2.5 meters taller because of its extended nozzle, which is designed for operation in space. 

Ground testing used a shorter nozzle section to avoid airflow instability at sea level and to help engineers model how the full engine will perform under vacuum conditions. Rocket Lab said that the work is “critical preparation for Neutron’s first flight.”

CEO Peter Beck told Stocktwits in April that Rocket Lab was “pushing very hard” to launch Neutron by the fourth quarter of 2026. “We’re on track, but you know it is a rocket program at the end of the day,” Beck said. He said that the challenge is not only reaching orbit, but proving Neutron can return and be reused. “If we just had to go up, it’s super easy, we’d be in orbit by now,” Beck said.

Space Force Win, Iridium Deal Fuel RKLB 

The engine milestone comes after Rocket Lab’s successful Victus Haze mission for the U.S. Space Force. Rocket Lab launched the mission 16 hours and 42 minutes after receiving notice, commissioned its Pioneer spacecraft within 38 hours and completed rendezvous and proximity operations in under 59 hours.

The mission was notable since Rocket Lab provided the launch vehicle, spacecraft and orbital operations under a single contract. Beck said that the company had set “the new standard in responsive space.” Rocket Lab is expected to continue operating the Pioneer spacecraft for additional Space Force exercises in orbit.

Earlier this month, Rocket Lab also agreed to acquire Iridium for about $8 billion, combining Rocket Lab’s launch and spacecraft manufacturing businesses with Iridium’s global communications network and more than 2.55 million subscribers. Beck called the combined company a “fully integrated self-launching space superpower.”

How Do Retail Traders Feel About RKLB?

On Stocktwits, retail sentiment for RKLB was ‘bearish’ amid a 675% surge in 24-hour message volumes.

One user said, “$RKLB shame of it is that POS spaceX stock is pulling down all space stock but watch what i tell you, in 3 years time RKLB will be a way better company and leading the space companies”

Another bullish user said, “$RKLB I have added 75 shares today, nothing crazy, just 5-10 at a time, more volatility jumps and drops to be expected”

RKLB stock has jumped 97% over the past year. 

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