Four of the RS-25s will eventually be used to carry an unmanned Orion spaceship deeper into the solar system, including on a possible mission to Mars. The launch system is based on three decades of research. For added power, the new RS-25 uses 25 percent more fuel than the one that powered the space shuttle. The SLS is designed to launch only once, unlike a shuttle.
The test shows just how much smoke the heat of the engine creates. Multiple 360 cameras were used to record the testing from a number of different vantage points, including one camera that was placed right inside the flame trench, which helps to direct the exhaust away from the launch pad, and ends up surrounded by smoke and water. The water in the trench is even vaporized enough to make a double rainbow.
The hot fire test was conducted at the Stennis Space Center in Mississippi in February. The entire test lasted more than six minutes, but the video was trimmed to a little over two minutes.
The Space Launch System is NASA’s largest rocket to date, designed to be adaptable for both unmanned and crewed missions. The RS-25 is the engine that powered the space shuttle during 30 years of operation. It’s one of the most tested large rocket engines in history, with more than 3,000 starts and more than 1 million seconds of total ground test and light ring time. NASA is upgrading the engines for the SLS with electronic controllers and new nozzle insulation. While the SLS is expected to have two variations with different boosters, the system uses four of the RS-25 engines in both cases.