NASA has completed a complex series of tests on one of the largest composite cryogenic fuel tanks ever manufactured, bringing the aerospace industry much closer to designing, building, and flying lightweight, composite tanks on rockets.

The demanding series of tests on the 18-foot (5.5-meter)-diameter tank were conducted inside a test stand at NASA’s Marshall Space Flight Center in Huntsville, AL. Engineers added structural loads to the tank to replicate the physical stresses launch vehicles experience during flight.

In other tests, the tank successfully maintained fuels at extremely low temperatures and operated at various pressures. Engineers filled the tank with almost 30,000 gallons of liquid hydrogen chilled to -423 degrees Fahrenheit, and repeatedly cycled the pressure between 20 to 53 pounds per square inch – the pressure limit set for the tests.