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The RS-25 rocket engine for NASA's future megarocket, the Space Launch System (SLS), was test-fired for about 8.5 minutes yesterday (July 25). The test, the third in a row for NASA, occurred at the agency's Stennis Space Center near Bay St. Louis, Mississippi. 

"In the heart of baseball season, NASA completed its equivalent of a clean inning, successfully testing the third RS-25 flight controller for use on the new Space Launch System (SLS) deep space rocket," NASA officials wrote in a statement. The test lasted about 500 seconds and was conducted on the A-1 Test Stand at Stennis, they added. [Watch:How NASA's Space Launch System Will Fly]

"With this latest test, NASA continues to set the stage for deep-space exploration missions, achieving another milestone toward launch of the first integrated flight of SLS and the Orion spacecraft, known as Exploration Mission-1," NASA officials said. "SLS will be powered at launch by four RS-25 engines, firing simultaneously to provide 2 million pounds [900,000 kilograms] of thrust and working in conjunction with a pair of solid rocket boosters to produce up to 8 million [3.6 million kg] pounds of thrust."

The four Aerojet Rocketdyne RS-25 engines that will be used on Exploration Mission-1 (EM-1) are former space shuttle engines, but the flight controllers that operate them will be new.

"The controller is the key modification to the engines and is characterized as the 'brain' that provides precision control of engine operation and internal health diagnostics, and allows communication between the RS-25 engine and the SLS," NASA officials said. "During launch and flight, the controller communicates with the SLS flight computers, receiving critical commands and returning engine health and status data." 

The first new RS-25 engine flight controller was tested in March, and a second test occurred in May. 

NASA is targeting a 2019 launch for EM-1. The mission will use an SLS rocket to launch an uncrewed Orion space capsule on a three-week trip around the moon. 

Editor's note: Space.com senior producer Steve Spaleta contributed to this story.

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.