Rocket Lab is making steady progress on the development of its Neutron vehicle, as the company reported fourth-quarter results that saw its contract backlog soar above $1 billion.

The space company reported a net loss of $50.5 million, or 10 cents per share, for the quarter. Year over year, Rocket Lab’s fourth-quarter net loss widened by about 36% as the company continues to spend heavily to create its Neutron rocket. Its full-year loss widened by a similar amount, to $182.6 million, or 38 cents per share.

Revenue grew 16% year over year in the fourth quarter to $60 million, up from $51.8 million. Its launch business made up just $8.5 million of that, as the company is coming off a multimonth hiatus in Electron missions, and its space systems made up the bulk, at $51.5 million.

Rocket Lab’s fourth-quarter revenue was just shy of the $62.9 million Wall Street expected, according to analysts surveyed by LSEG, formerly known as Refinitiv, while the net loss of 10 cents per share was in line with estimates.

The company’s backlog of orders more than doubled year over year, bolstered significantly by a $515 million satellite contract from the Pentagon’s Space Development Agency. Rocket Lab CEO Peter Beck noted in a press release that 2023 was “a record year for securing Electron” launch deals, with the company adding 25 contracts. Launches make up $248 million of Rocket Lab’s backlog, with the remainder representing its growing space systems business.

Shares of Rocket Lab slipped 5% in after-hours trading from its close at $4.71.

Rocket Lab forecast first-quarter revenue between $92 million and $98 million.

Rocket Lab gave multiple updates on the progress it’s making in developing its next-generation Neutron rocket, which aims to compete with the likes of SpaceX. Since unveiling its plans for Neutron in 2021, Rocket Lab has been spending heavily to debut the vehicle in the next year or so.

The company’s fourth-quarter investor presentation detailed several of the Neutron milestones achieved so far, including the beginning of production of rocket parts for the first launch, software simulations of launches and the completion of early testing of the Archimedes engines that will power the rocket.

Rocket Lab also detailed milestones coming up this year for Neutron, including Archimedes engine testing and structural testing of the Neutron rocket’s nose cone.

Additionally, Rocket Lab announced the expansion of its line of spacecraft products. Building upon the success of its Photon satellite bus, the company unveiled three additional spacecraft, called Lightning, Pioneer and Explorer, for a variety of customer missions, from low Earth orbit communications satellites to scientific deep space exploration of other planetary bodies.

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