NASA successfully tested rocket engine No. 2059 at Stennis Space Center in Mississippi, which fired for 500 seconds. The next time it lets loose some hot fire, it—along with the help of three other RS-25 rockets—will propel humans deep into space aboard the new Space Launch System vehicle.
These flight engines are holdovers from NASA’s Space Shuttle Program, used from 1981 to 2011 to power 135 space shuttle missions. Eventually, the hope is that they will take astronauts to Mars.