We continue to make progress toward the first launch of our Space Launch System (SLS) rocket for the Artemis I mission around the Moon. Engineers at NASA’s Stennis Space Center near Bay St. Louis, Mississippi are preparing for the last two tests of the eight-part SLS core stage Green Run test series.
The test campaign is one of the final milestones before our SLS rocket launches America’s Orion spacecraft to the Moon with the Artemis program. The SLS Green Run test campaign is a series of eight different tests designed to bring the entire rocket stage to life for the first time.
As our engineers and technicians prepare for the wet dress rehearsal and the SLS Green Run hot fire, here are some numbers to keep in mind:
The SLS rocket’s core stage is the largest rocket stage we have ever produced. From top to bottom of its four RS-25 engines, the rocket stage measures 212 feet.
For each of the Green Run tests, the SLS core stage is installed in the historic B-2 Test Stand at Stennis. The test stand was updated to accommodate the SLS rocket stage and is 35 stories tall – or almost 350 feet!
4 RS-25 Engines
All four RS-25 engines will operate simultaneously during the final Green Run Hot Fire. Fueled by the two propellant tanks, the cluster of engines will gimbal, or pivot, and fire for up to eight minutes just as if it were an actual Artemis launch to the Moon.
Our brawny SLS core stage is outfitted with three flight computers and special avionics systems that act as the “brains” of the rocket. It has 18 miles of cabling and more than 500 sensors and systems to help feed fuel and direct the four RS-25 engines.
The stage has two huge propellant tanks that collectively hold 733,000 gallons of super-cooled liquid hydrogen and liquid oxygen. The stage weighs more than 2.3 million pounds when its fully fueled.
114 Tanker Trucks
It’ll take 114 trucks – 54 trucks carrying liquid hydrogen and 60 trucks carrying liquid oxygen – to provide fuel to the SLS core stage.
6 Propellant Barges
A series of barges will deliver the propellant from the trucks to the rocket stage installed in the test stand. Altogether, six propellant barges will send fuel through a special feed system and lines. The propellant initially will be used to chill the feed system and lines to the correct cryogenic temperature. The propellant then will flow from the barges to the B-2 Test Stand and on into the stage’s tanks.
All eight of the Green Run tests and check outs will produce more than 100 terabytes of collected data that engineers will use to certify the core stage design and help verify the stage is ready for launch.
For comparison, just one terabyte is the equivalent to 500 hours of movies, 200,000 five-minute songs, or 310,000 pictures!
The B-2 Test Stand has a flame deflector that will direct the fire produced from the rocket’s engines away from the stage. Nearly 33,000 tiny, handmade holes dot the flame deflector. Why? All those minuscule holes play a huge role by directing constant streams of pressurized water to cool the hot engine exhaust.
One Epic First
When NASA conducts the SLS Green Run Hot Fire test at Stennis, it’ll be the first time that the SLS core stage operates just as it would on the launch pad. This test is just a preview of what’s to come for Artemis I!
The Space Launch System is the only rocket that can send NASA astronauts aboard NASA’s Orion spacecraft and supplies to the Moon in a single mission. The SLS core stage is a key part of the rocket that will send the first woman and the next man to the Moon through NASA’s Artemis program.