Ursa Major has quietly closed $100 million in new funding, according to documents viewed by TechCrunch and multiple sources.

Funders to the Series D include BlackRock and Space Capital. The funding was reportedly closed last October.

The new capital came less than a year after the company closed an $85 million Series C. All told, the company has now raised around $234 million and sought the funding at a $400 million pre-money valuation.

An Ursa Major spokesperson declined to comment “on rumors or speculation.”

Ursa, led by CEO Joe Laurienti, is building a 5,000-pound liquid oxygen and kerosene engine called Hadley and a much larger, 10x more powerful Ripley engine with a 50,000-pound thrust. The company eschews the vertical integration paradigm that has historically dominated the aerospace industry. Instead, it focuses solely on the engine, one of the trickiest parts of a rocket to develop.

“We really like the notion that we are a technology development company, and the companies that are flying rockets today should not be flying the same engine that they architected for their rocket 10 years ago,” Laurienti told TechCrunch in an interview last year. “That’s the paradigm we see in vertical integration.”

Ursa’s public customer pool includes small launch companies Astra, Phantom Space and Stratolaunch. The company has also scored an engine delivery contract with the U.S. Air Force.