A liquid hydrogen storage tank is photographed at Launch Pad 39B on Nov. 8, 2019, at NASA’s Kennedy Space Center in Florida. The agency’s Exploration Ground Systems oversaw testing of the pad’s cryogenic systems – the infrastructure that will support the flow of liquid hydrogen and liquid oxygen from the storage tanks to the Space Launch System (SLS) rocket – in preparation for the launch of SLS with the Orion spacecraft atop for the uncrewed Artemis I mission. Each of the liquid hydrogen and liquid oxygen tanks can hold more than 800,000 gallons of propellant. The liquid hydrogen, lighter than liquid oxygen, will make its way from the tank to the rocket using gaseous hydrogen to pressurize the sphere at the time of launch, while the liquid oxygen will be sent to the rocket via pumps.