SLS’ Core Stage is Finally Ready for Construction

NASA’s Space Launch System takes flight. Image Credit: Boeing

NASA has passed yet another milestone in the ongoing development of its Space Launch System (SLS)—the rocket that will launch Orion to the Moon and beyond. The rocket’s core stage is finally ready to move from concept to construction. 

SLS is NASA’s next big, heavy lift vehicle that will surpass the Saturn V in size and power. And it’s sort of like a Saturn V merged with the space shuttle’s launch system. The rocket has a central core stage analogous to the Saturn V’s first stage with two external boosters reminiscent of the shuttle’s. The spacecraft—Orion—will sit on top like the Apollo command module sat atop the Saturn.

This latest SLS’ preliminary design review was held on Thursday, December 20, at NASA’s Marshall Space Flight Center in Huntsville, Ala. In attendance were agency representatives as well as representatives from Boeing; the aerospace company’s Exploration Launch Systems in Huntsville will build the core stage. The review was held at Marshall as it’s managing the whole SLS program.

This expanded view of the SLS/Orion shows how the rocket and spacecraft fit together. The core stage is the central piece of the puzzle. Image Credit: NASA

This review was designed to verify that the core stage’s design meets the necessary system requirements—within acceptable risk levels, budget constraints, and schedules, of course. Specifically, it was designed to make sure that the core stage will be able to integrate safely with other elements, like the rocket’s main engines, solid rocket boosters, the crew capsule, and the launch facilities at NASA’s Kennedy Space Center in Florida. To prove its design is sound, the core stage’s designers provided an in-depth assessment to a board of engineers—largely propulsion and design experts—from across the aerospace industry.

And the core stage passed; it’s finally cleared to be built. Passing this latest review is significant not only because it means SLS can move forward, but also because of how fast the process has been. “Passing a preliminary design review within 12 months of bringing Boeing on contract shows we are on track toward meeting a 2017 launch date,” said Tony Lavoie, manager of the SLS Stages Element at Marshall. “We can now allow those time-critical areas of design to move forward with initial fabrication and proceed toward the final design phase—culminating in a critical design review in 2014—with confidence.”

Right now, the Orion spacecraft is further along in its development than SLS. There’s a test model already built, and boilerplate spacecraft have gone through splashdown and parachute tests. But it’s important that the spacecraft doesn’t get too far ahead of its rocket. “Each individual element of this program has to be at the same level of maturity before we can move the program as a whole to the next step,” said SLS Program Manager Todd May. “The core stage is the rocket’s central propulsion element and will be an optimized blend of new and existing hardware design. We’re building it with longer tanks, longer feed lines, and advanced manufacturing processes. We are running ahead of schedule and will leverage that schedule margin to ensure a safe and affordable rocket for our first flight in 2017.”

Though the SLS will eventually evolve to a larger and more powerful configuration, the core stage will remain the core of the design. Image Credit: NASA

The core stage will be built at NASA’s Michoud Assembly Facility in New Orleans. The centre has modified its facilities and ordered new materials to bring cutting edge technology into SLS’ construction. Building rockets is a long-standing tradition at Michoud; the centre has built components for NASA’s spacecraft and rockets for decades, most notably the space shuttle’s external tanks.

With this latest review milestone passed, things are looking good for SLS to fly on schedule. The first flight, which will have the rocket configured for a 70-metric-ton launch, will take an unmanned Orion spacecraft past the Moon. Subsequent launches will see the rocket send men and machines even further.


  1. AmericaSpace- Thanks for the great write-up. I really enjoying your website and reading the various articles. On SLS – can’t wait to see this thing fly!

  2. I am glad to see this moving forward, although I am not too fond of the SLS designation. It reminds me less of the Saturn V and more of a Saturn sedan.

  3. Going back to the Apollo ERA the Saturn V it could have been reconfigured for other Space deployment and using a a different kind of Faring to house the space equpiment that the SaturnV could have deployed during the the 1960’s,70’s,and 80’s it would have saved NASA a lot of Dollars if it two ways of useing the Saturn V.

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