Wet Dress Rehearsal Exercise

Teams at NASA’s Stennis Space Center performed a wet dress rehearsal exercise with the new Space Launch System core stage Dec. 20, 2020. The test – the seventh in an eight-test Green Run series – involved rehearsal of a countdown to hot fire of the stage’s engines, including the loading of 733,000 pounds of liquid hydrogen and liquid oxygen propellants. This image shows liquid hydrogen being safely vented and burned as it naturally warms and boils off.