The fourth and final structural test article for NASA???s Space Launch System (SLS) core stage was unloaded from NASA???s barge Pegasus at NASA???s Marshall Space Flight Center in Huntsville, Alabama, Tuesday, July 9, 2019. The nearly 70-foot-long liquid oxygen (LOX) tank structural test article was manufactured at NASA???s Michoud Assembly Facility in New Orleans and is structurally identical to the flight version. Next, crews will load it into a test stand at Marshall for critical testing. The liquid oxygen tank is one of two propellant tanks in the rocket???s core stage that will produce more than 2 million pounds of thrust to help launch Artemis 1, the first flight of NASA???s Orion spacecraft and SLS, to the Moon. Where: Huntsville, Alabama, United States When: 09 Jul 2019 Credit: NASA/Fred Deaton/Cover Images **Editorial use only**