NASA is going to light a massive fire in the Utah desert tomorrow morning. The space agency plans to test out one of the solid rocket boosters that will be used on the Space Launch System (SLS), the giant expandable rocket that NASA is building to take humans into deep space. For the test, the engines on the booster will be ignited for two minutes at Orbital ATK’s test facilities in Promontory, Utah. The booster itself won’t be going anywhere, since it will be horizontal and constrained, but the huge combustion will send an impressive plume of flames and rippling exhaust clouds shooting out into the desert. The test is scheduled to begin at 10:05AM ET.
As its name implies, the solid rocket booster — manufactured by Orbital — is meant to give NASA’s SLS an extra boost. Two of the boosters will be strapped onto either side of the main body of the rocket during lift off and will remain attached to the vehicle for the first two minutes of flight. Standing at about 17 stories tall, each booster burns about 5.5 tons of propellant per second and provides about 3.6 million pounds of maximum thrust. According to Orbital, that’s more power than 14 four-engine Boeing 747s have at take off.
This is the second time NASA has conducted a ground test of the SLS booster. In March 2015, the booster was heated to 90 degrees Fahrenheit. That’s the highest temperature the propellant can be, with the engine still functioning properly. This time around, NASA wants to see how the booster will handle much colder propellant, at around 40 degrees Fahrenheit. That’s supposedly the coldest the booster’s motor can handle. Both tests are meant to see how the booster can sustain extreme temperatures.
This is the last time we’ll see an SLS solid rocket booster light up again for a while. The next time the boosters are fired will be on the first test flight of the SLS. That mission, called Exploration Mission-1 (EM-1), is set to take place in late 2018. The rocket will launch an uncrewed version of the Orion crew capsule that NASA has been working on for the past decade. Though no people will be on board, EM-1 will carry to space a number of research satellites, including a lunar laser that will help map ice at the Moon’s south pole and an "asteroid scout" that will map an asteroid near Earth.
After that first test flight, SLS may not fly again for another five years. NASA is aiming to launch the second SLS flight, which will take people into space for the first time, in 2021. But the space agency has said that it could potentially slip to 2023.