The engine test stand will play a key role in the company's development of next generation technology that will make important advancements in improving fuel efficiency and reducing emissions, the company said.
Testing will include noise, crosswind, endurance and other tests on the latest civil aircraft engines, among them the Trent 1000 that powers the Boeing 787 Dreamliner.
"Our decision to first build, and now expand, the Rolls-Royce Outdoor Jet Engine Test Stand here at Stennis embraces the spirit of partnership with the State of Mississippi," said James M. Guyette, president and chief executive officer of Rolls-Royce North America said at an opening ceremony. "This relationship continues to grow, which is a direct result of a very positive public-private partnership.
"Rolls-Royce is investing in America because our collective innovation, competitiveness and cooperative spirit -- and we find the State of Mississippi is the perfect location to expand our operations."
The engine test facility, the first by the company outside Britain, was first constructed in 2007.
Rolls-Royce said the expanded facility cost $50 million.