Launcher's E-2 rocket engine, which was printed as a single piece of metal. Launcher

A small start-up based in the Brooklyn Navy Yard is staking its claim among the next generation of rocket companies: by developing a rocket engine that it says is the world's largest 3D printed in a single piece. The simply-named company, Launcher, provided CNBC with a first look at the company's E-2 engine, which was made in Germany by AMCM using its specialized M4K printer. Launcher has only five full-time employees but credits its ability to develop E-2 quickly to the advances made in 3D printing. "With 3D printing, we're now in a world where a start-up like us can now access [advanced] liquid oxygen propulsion technologies," Launcher founder Max Haot told CNBC.

The staff of rocket start-up Launcher at the company's headquarters at the Brooklyn Naval Yard in New York City. Launcher

Haot founded Launcher in 2017, after he sold his internet video business Livestream to Vimeo. Launcher plans to spend a decade building a six-story-tall rocket that will send small spacecraft to orbit. Launcher's rocket is priced to that smaller market as well, with plans to sell missions for about $10 million a launch. Beyond Launcher's headquarters at the Brooklyn Navy Yard, which is now an industrial park, the start-up has a test facility on Long Island at the Naval Weapons Industrial Reserve Plant. Launcher has completed several minutes worth of test fires of its E-1 engine on Long Island. The company expects to begin test firing the E-2 engine in the second half of this year.

A Launcher rocket engine test on Long Island, New York

The E-2 engine is the key next step in Launcher's plan if test flights are to begin in 2024. It's a "closed cycle" combustion system, which Haot said is "the most powerful" engine system. This is the same approach that SpaceX's new Raptor engine uses, to eek out the most efficiency from an engine as possible. The 3D printing parts will also help Launcher's development timeline. AMCM took "about a week" to print the E-2 engine, said AMCM's head of sales, Christian Waizenegger. This makes M4K the first of its kind, as it combines high-quality machining with the ability to print large parts. There is controversy about whether E-2 is the world's largest rocket engine that was 3D printed in a single piece. Other rocket start-ups are using 3D printed technologies to widely varying degrees. For example, Los Angeles-based Relativity Space is working to build nearly entire rockets out of 3D printed parts. And U.K.-based Orbex unveiled an engine earlier this month it claims is "the world's largest. Like Launcher's E-2, the Orbex engine was manufactured in a single piece.

A computer rendering of Launcher's rocket. Launcher