Rocket Lab Corp. (RKLB  ) shares slipped in early trading Tuesday after the company signaled a narrowing window for the first flight of its Neutron rocket. Stage 1 tank production still aligns with delivering Neutron to the launchpad in the fourth quarter of 2026, but Rocket Lab stopped short of reaffirming a first flight before year-end.

Neutron is Rocket Lab's partially reusable, medium-lift rocket, designed to carry roughly 13 tons to low Earth orbit - about 43 times Electron's capacity. It's built for satellite-constellation deployment, national-security missions and eventual exploration of the Moon and Mars, and it's meant to compete with SpaceX (SPCX  ) Falcon 9 in the medium-lift launch market.

Neutron Timeline Slips Into Question

Rocket Lab CEO Peter Beck addressed the timeline directly on the earnings call.

"Production currently lines up with the target delivery of Neutron to the pad in Q4 2026. While the window for an end-year launch is narrowing, the work we're doing now is about risk trading, balancing the timing of our first launch against how quickly and seamlessly we can scale at tenth launch," he said.

The timeline risk overshadowed a record quarter. Second-quarter GAAP net loss narrowed to eight cents per share, while revenue jumped 62% year-over-year to a record $234.1 million, beating the consensus estimate. GAAP gross profit came in at $84.6 million, with non-GAAP gross margin at 41.5%.

Backlog told a similar story, climbing to a record $2.36 billion, up 137% year-over-year.

"Q2 2026 saw our backlog grow to $2.36 billion - another record - which, combined with new deals in the period since, equates to more than $1 billion in new contracts across launch and space systems already entered into in Q3," Beck said.

New launch contracts across Electron, HASTE and Neutron totaled more than $437 million during Q2 and the period since, lifting the total launch backlog past 90 missions.

Looking Ahead

Looking ahead, Rocket Lab guided third-quarter revenue between $250 million and $265 million, above the roughly $236 million Street estimate. Management also flagged a tighter non-GAAP gross margin of 35% to 37% and an adjusted EBITDA loss of $17 million to $23 million.

Cash burn remains a watch item. Free cash flow was negative $110.1 million in the quarter. Management expects elevated negative free cash flow to persist, with positive cash flow unlikely until 18 to 24 months after Neutron's first successful test flight.

RKLB Stock Price Activity: Rocket Lab stock was down 3.85% at $76.95 at the time of publication Tuesday, according to data from Benzinga Pro.