The Boeing-built Space Launch System (SLS) core stage is positioned in the B-2 Test Stand at NASA’s Stennis Space Center near Bay St. Louis, Mississippi. To practice handling and lifting the stage, work crews first used a “pathfinder” of the same shape, size and weight.

NASA photo

Boeing teams on the ground – and 22 stories above it – at Stennis Space Center have been preparing the massive B-2 test stand to receive the Space Launch System (SLS) rocket’s 212-foot tall core stage – the largest NASA has ever built or tested. After days of careful handling and positioning, the core stage has been lifted into the stand.

Modifications to the historic Apollo and space shuttle-era test stand allow NASA and industry partners access to the core stage in advance of its first integrated “smoke and fire” test, called Green Run.

The term “green” refers to the new hardware that will work together to power the stage, and “run” refers to operating all the components together simultaneously for the first time.

The test program for the core stage at Stennis will take place over several months. Engineers will turn the components on one by one through a series of functional checks to assess the integrated core stage before and after fueling. The core stage fuel tanks hold 733,000 gallons of liquid oxygen and liquid hydrogen to power its four Aerojet Rocketdyne RS-25 engines.

The program will culminate in an eight-minute static fire through a nominal "launch" and "ascent" while the stage remains locked into the test stand.

It will be the first time the stage will be fully operational, from the avionics in the top of the core stage to the engines at the bottom.

In the actual launch, the first eight minutes of launch also will include two solid rocket boosters, attached to the core stage, to produce a total 8.8 million pounds of thrust.

Using powerful computational tools, paired with decades of NASA flight data, Boeing and NASA tested the SLS throughout design and development to save time and money for an expedited first flight of this revolutionary launch system, while maintaining safety and quality.

After Green Run, the core stage and its engines will be evaluated, refurbished as needed, and then shipped to NASA’s Kennedy Space Center in Florida. There, the stage will be mated with the rest of the SLS rocket elements, including the twin solid rocket boosters that will be attached to the core stage and the Interim Cryogenic Propulsion Stage that will provide the final push to send the Orion spacecraft into lunar orbit for the Artemis I mission.

The curtain will rise again for the integrated Orion/SLS opening performance at Kennedy’s launch pad.

Before NASA’s deep space rocket, the Space Launch System (SLS), launches from Kennedy Space Center in Florida to send NASA’s Orion spacecraft to the moon, its Boeing-built core stage will be run through a series of tests called Green Run. (NASA graphic)