Known as "topping out," the addition of the test cell dome on April 13, 2011, atop NASA's A-3 Test Stand at the John C. Stennis Space Center marked a new milestone for the project. It's the most recent in a long line of milestones as the stand, which will be used to test next-generation rocket engines meant to shuttle humans into deep space, has been in the works since ground was broken back in 2007.
"The stand will use a series of chemical steam generators to create a vacuum that allows operators to test full-scale engines at simulated altitudes up to 100,000 feet," NASA's website explains. "The A-3 stand is the first large test structure to be built at Stennis since the facility was established to test the Saturn V rocket stages that helped carry Apollo astronauts to the moon and is scheduled for activation in 2013."
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