NASA's 1st SLS Megarocket Core Loaded Onto Barge Ahead of Key Engine Test

The first completed core stage of NASA’s Space Launch System rocket is guided toward the agency’s Pegasus barge on Jan. 8, 2020, ahead of its forthcoming journey to NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Teams rolled the core out from NASA’s Michoud Assembly Facility in New Orleans to the barge in preparation for the core stage “green run” test series.
The first completed core stage of NASA’s Space Launch System rocket is guided toward the agency’s Pegasus barge on Jan. 8, 2020, ahead of its forthcoming journey to NASA’s Stennis Space Center near Bay St. Louis, Mississippi. Teams rolled the core out from NASA’s Michoud Assembly Facility in New Orleans to the barge in preparation for the core stage “green run” test series. (Image credit: NASA)

The heart of NASA's first Space Launch System (SLS) megarocket is on the move.

The 212-foot-long (65 meters) SLS core stage rolled out of NASA's Michoud Assembly Facility in New Orleans Wednesday (Jan. 8) and was loaded onto a barge, agency officials announced. 

That barge will soon depart for NASA's Stennis Space Center in Mississippi, where the booster will endure a crucial, months-long "green run" test designed to demonstrate its fitness to send astronauts to the moon, Mars and other deep-space destinations. 

Related: Watch NASA's SLS Megarocket Get Ready for US Moon Missions (Video)

A jazz band from a local high school escorted the booster out to the road Wednesday, said John Shannon, SLS vice president and program manager at Boeing, the prime contractor for the rocket's core stage.

"It was just a fantastic way to celebrate this historic milestone — sending the most complicated vehicle that's ever been built at Michoud, by far, out on its way to the test facility," Shannon said during a call with reporters on Wednesday afternoon. 

The journey to Stennis will take about 9 hours, he added. The voyage is not yet underway, however; the travel date depends on the weather.

The SLS is key to NASA's human spaceflight plans. The rocket's first iteration, known as the Block 1, will stand 322 feet (98 m) tall and generate 8.8 million lbs. of maximum thrust at liftoff — 15% more than the agency's iconic Saturn V rocket, which launched the Apollo missions to the surface of the moon. The SLS core stage's four RS-25 engines will provide about 2 million lbs. of that thrust; the rest will come from two strap-on solid rocket boosters.

The future Block 2 SLS will be even brawnier, producing nearly 12 million lbs. of maximum thrust at liftoff.

NASA's Space Launch System rocket’s core stage, complete with all four RS-25 engines, is transported from NASA’s Michoud Assembly Facility in New Orleans to the agency’s Pegasus barge on Jan. 8, 2020. (Image credit: NASA)

The core that just left Michoud will fly in the Block 1 configuration, on the very first flight of the SLS. That mission, known as Artemis 1, will launch NASA's Orion capsule on an uncrewed journey around the moon. Artemis 1 is currently scheduled to launch no earlier than November of this year.

But the SLS core has to pass the green run before Artemis 1 can get off the ground. That test series will put the core stage through its paces, checking out its many complicated and interconnected subsystems and ultimately lighting up the four RS-25 engines for a full 8 minutes — the amount of time they'll fire on an actual mission to the moon. (The "green" in "green run," by the way, refers to the previously untested nature of the hardware on the stand.) 

If everything goes well with the green run and Mother Nature cooperates, the test campaign could wrap up by July or August, Shannon said. But weather issues, and the need to refurbish the core after various subtests, may well push completion into October, he added.

After the green run is done, the core stage will take another, much longer barge trip — an eight- to 12-day trek around Florida's west coast and back up the state's east side to NASA's Kennedy Space Center, the Artemis 1 launch site.

Related: Photos: NASA's Space Launch System for Deep-Space Flights

Artemis 1, in turn, is just the first of many planned missions in NASA's Artemis program, which seeks to land two astronauts near the lunar south pole by 2024 and establish a long-term, sustainable human presence on and around the moon by 2028. 

Artemis 2, another lunar flyby, will be the first crewed flight of SLS and Orion. That mission is currently targeted for late 2022.

The SLS program has endured a series of cost overruns and delays. Indeed, a 2015 assessment estimated that the first core stage would be done by the end of 2017, Shannon said. 

"So, we're about two years late," he said. "Boeing completely owns that."

Shannon cited two main issues that led to this latest delay. The first involved the new tooling used to weld the core stage together, as well as problems with the welding process itself. 

"The other issue, I think, that caused us some difficulty was, we really underestimated the complexity of building the engine section, which is the very bottom of the rocket that holds all of the propulsion elements and all of the TVC [thrust vector control] and hydraulic elements," Shannon said.

But Boeing learned a great deal from this first build and is already applying the lessons, he added, stressing that the second SLS core is coming together at Michoud 40% faster than the first one did.

NASA Deputy Administrator Jim Morhard — who also participated in today's call, along with NASA SLS Program Manager John Honeycutt — said that delays are to be expected when building something as big and complex as an SLS core stage for the first time. And Morhard stressed that the future is bright for SLS and the Artemis program.

"There's a lot more to come," Morhard said.

Mike Wall's book about the search for alien life, "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), is out now. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.

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Mike Wall
Senior Space Writer

Michael Wall is a Senior Space Writer with Space.com and joined the team in 2010. He primarily covers exoplanets, spaceflight and military space, but has been known to dabble in the space art beat. His book about the search for alien life, "Out There," was published on Nov. 13, 2018. Before becoming a science writer, Michael worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz. To find out what his latest project is, you can follow Michael on Twitter.

  • k-ho
    The fact that SLS is assembled in one state, travels to another state for testing and neither of those states is Florida shows why the old-school funding model is so expensive -- and so intractable. Michoud, Stennis, Huntsville, Houston, Kennedy. Congress spreads the pork everywhere.
    Reply
  • kwyzc
    It's great!
    Reply
  • lrobertsonbooks
    Unless the 1st stage is reusable, Boeing is 10 years behind SpaceX and can't hope to compete in the long run.
    Reply
  • Bruzote
    k-ho said:
    The fact that SLS is assembled in one state, travels to another state for testing and neither of those states is Florida shows why the old-school funding model is so expensive -- and so intractable. Michoud, Stennis, Huntsville, Houston, Kennedy. Congress spreads the pork everywhere.
    lrobertsonbooks said:
    Unless the 1st stage is reusable, Boeing is 10 years behind SpaceX and can't hope to compete in the long run.

    That just means they can ask for additional funding or tax breaks funded by you and I! Corporate and upper middle class welfare is always OK, don't you know?
    Reply
  • TEAMSWITCHER
    lrobertsonbooks said:
    Unless the 1st stage is reusable, Boeing is 10 years behind SpaceX and can't hope to compete in the long run.

    I agree that reusability is a good thing, but... I don't think that Starship and BFR are the right direction. It's just too damn big. Every major accomplishment in Space Exploration has been achieved by limiting weight. The Lunar Module is a prime example, it got us to the surface of the Moon, because it wasn't a huge second stage of a rocket - it was a small excursion vehicle. Elon Musk is pursuing a dead end.. Like Howard Hughes, Starship/BFR will be a Stainless Steel Goose.
    Reply
  • East Memphis
    The Senate Launch System (SLS) is so over budget and behind the times that this monster should have been cancelled the moment a Falcon 9 was reused. I remember reading about the launch tower that costs $1B to rebuild, a money savings effort. Then, they need a SECOND launch tower because the one they just spent a billion on won't be usable except for ONE FLIGHT. Unbelievable. Now, they're going to throw away a full booster in this test. Don't forget the elaborate test stand that probably cost $500 million for a one off test. For just this money, the Falcon Heavy was developed, tested and flown throwing Elon't groovy car into Mars orbit. That's the way to test things.

    The problem with NASA is it has become a jobs agency for fat cat in Washington and not an exploration program. NASA should stick to unmanned satellites and leave launchers to those who can actually do it.
    Reply
  • GeoXXX
    lrobertsonbooks said:
    Unless the 1st stage is reusable, Boeing is 10 years behind SpaceX and can't hope to compete in the long run.
    Reusability is quite an accomplishment but it has yet to be shown that it is actually more cost efficient.
    Reply
  • newtons_laws
    GeoXXX said:
    Reusability is quite an accomplishment but it has yet to be shown that it is actually more cost efficient.
    Well if it is more cost efficient then that will start to be reflected in the launch costs charged by SpaceX to their customers becoming lower than that of their (non reusable) competitors - and I believe things are already starting to move in that direction, e.g https://fortune.com/2017/06/17/spacex-launch-cost-competition/
    Reply