• 3D-printing specialist Relativity Space signed an expansion deal with NASA's Stennis space center in Mississippi.
• Relativity will build new infrastructure and facilities on more than 150 acres at the NASA complex.
• The additional facilities are key to Relativity's development of a reusable rocket called Terran R.

Relativity Space, which 3D-prints rockets, said Tuesday that it signed a deal to expand its presence at NASA's Stennis Space Center in Mississippi and create one of the country's largest rocket engine test facilities.

Based in Long Beach, California, Relativity's rockets are designed to be almost entirely 3D-printed, an approach the company says is less complex and faster to build or modify, compared with traditional rockets.

The additional facilities at Stennis in Mississippi will be key to Relativity's development of a reusable rocket called Terran R, which is expected to debut in 2025 and compete against some of the most powerful rockets on the market, such as SpaceX's Falcon 9, with the goal of being fully reusable.

"We're looking forward to writing some new history at Stennis through an incredibly large new expansion of development and test capabilities," Relativity cofounder and CEO Tim Ellis said in a statement.

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Relativity earlier this year said it has signed a backlog worth over $1.2 billion in contracts for launches on the Terran R.

Relativity said it will build multiple testing stands, office buildings and a hangar for its vehicles on the more than 150 acres at the NASA complex. The area hasn't been used by the agency and is adjacent to existing rocket engine testing areas. The company is already operational at Stennis, with agreements for seven engine test stands that have seen Relativity conduct more than 2,000 tests to date.

The company has already begun testing versions of the Aeon R engines that will power the Terran R rockets, and plans to begin full testing of the engines in late 2023 at the expansion.

Relativity has raised just over $1.3 billion in capital to date and has nearly 1,000 employees at facilities in California, Florida, Mississippi, Washington state and Washington D.C.

NASA's director of Stennis Rick Gilbrech said in a statement that the agency welcomed "the growth of this valued partnership" and called Relativity "a respected member" among those at the center since the company arrived in early 2018.