The Industrial Science Report: Inside NASA and Boeing’s SLS core stage build for Artemis II

This week on The Industrial Science Report, I’m devoting the entire week to the historic Artemis II mission that launched last week on April 1, returning U.S. astronauts to the Moon in our first lunar fly-by since the Apollo era. I, and many fellow Gen-Xers, watched nervously as the spacecraft safely launched. (For the younger Millennial and Gen Z and Alpha audience, IYKYK; for the rest of us, if you know, you know.)

The first uncrewed Artemis mission flew a successful test flight around the Moon in 2022. And Artemis III, targeted for mid-2027, will serve as another critical systems validation flight to dock with commercial landers in low-Earth orbit. This is all paving the way for Artemis IV in 2028, the mission that will return humans to the lunar surface. Artemis astronauts will investigate the lunar surface and learn to live and work there. 

The Moon is a destination in itself, with hopes for a future lunar ecosystem. However, the Moon also provides resources to reach farther into space, serving as the starting point for NASA to eventually reach Mars. 

Much of the manufacturing for the Artemis mission was done at NASA’s Michoud Assembly Facility in New Orleans, an 829-acre government-owned, contractor-operated component of the George C. Marshall Space Flight Center.

Thousands of manufacturers were involved in crafting the Orion spacecraft. This is the first in a series of articles that will dive into some of the key manufacturers and new innovations for the Artemis II mission, focused on the core vehicle and propulsion systems.

Boeing’s Space Launch System core stage

Boeing is an American aerospace and defense corporation and one of the world’s largest commercial jetliner manufacturers. Headquartered in Arlington, Virginia, it designs, builds, and services aircraft, space systems, and military platforms in more than 150 countries. Boeing maintains a workforce in more than 65 countries and a supplier base of more than 20,000 partners, and is a key contractor to the U.S. Department of Defense and NASA.

Innovations in industrial science: assembly facility and vehicle integration tooling, new fin-like strakes, and friction stir welding

This core stage and future Artemis mission stages are being built at the Michoud Assembly Facility, which includes the largest friction stir welding tool in world. It is used to join the aluminum-lithium tank sections with stronger, lighter joints. The facility can build several core stages simultaneously with the large welding machines. There, the core stage is outfitted with avionics, thermal protection systems, propulsion systems, and other internal hardware. After the structure is fully assembled, the four engines are added.

SLS construction took a big engineering step forward inside the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center in Florida, where the pieces built at Michoud were put together. The VAB’s High Bay 2 is tall enough to facilitate the vertical integration of the SLS core stage inside the facility.

The enormous building can suspend the fully assembled SLS 225 feet in the air to complete work before it is stacked on the mobile launcher. Technicians have 360-degree tip to tail access to the core stage, and the vertical capability allows them to do parallel processing from top to bottom, which is a much more efficient way to build core stages. 

Michigan-based Futuramic Tool and Engineering led the design and build of the Core Stage Vertical Integration Center tool, which holds the core stage in a vertical position. High Bay 2 tooling was originally scheduled to begin with Artemis III, but the team was able to complete it earlier, effectively doubling the usable manufacturing space with the VAB. It also frees up space at Michoud for future SLS core stages.

After the Artemis I launch in 2022, Boeing and NASA evaluated post-flight data and discovered the SLS rocket experienced higher-than-expected vibrations near the solid rocket booster attachment points. The vibration was determined to have been caused by unsteady airflow in the gap between the core stage and the two solid rocket boosters. After wind tunnel testing and computations fluid dynamics simulations, the team added four strakes (thin, fin-like metal structures) to the core stage to reduce vibrations by steadying the airflow.

The stage also integrates modern digital engineering practices, including model-based design and simulation, to validate performance before physical production.

NASA’s SLS rocket, powered by a Boeing-built core stage, is the only super-heavy lift rocket ever built for deep space. It integrates legacy propulsion (Space Shuttle–derived RS-25 engines) with modern digital engineering and advanced welding processes. The heritage engines also saved time and cost in developing the next generation. Model-based design, digital twins, and tighter tolerance control across massive assemblies were a major step forward in designing large, safety-critical structures. The stage also integrates modern digital engineering practices, including model-based design and simulation, to validate performance before physical production. The extensive pre-flight testing shows a strong eye for safety, as well as the structural design simulations and testing with terabytes of data done before anything was ever built.

From Challenger to Artemis: Why safety still feels personal in spaceflight

If you don’t know why Gen X collectively breathed a sigh of relief with the successful launch of the Artemis II crewed mission, many of us watched the Challenger explosion live at our elementary, middle, and high schools. I was in 2nd grade during the 1986 tragedy, and I do not have a memory of watching the event at school, or have blocked it out. However, my husband, who is five years older than me and in 7th grade at the time, has recounted the experience to me so vividly, it’s almost become my memory too.

His class, and many others across the country, had been waiting in anticipation of the launch with teacher Christa McAuliffe for some time, studying and discussing the significance of the launch. As the class watched the launch live on a short, thick TV wheeled into the classroom on a tall cart, the shuttle exploded 73 seconds into its mission. His teacher shut off the TV, wheeled the cart out of the classroom, and they continued along with their day and never said a word about what they all just witnessed.

It feels necessary to be so focused on bringing the astronauts home safely.

The distinctive orange color of the SLS core stage comes from its spray-on foam insulation, a critical part of the rocket’s thermal protection system. This insulation, along with materials like cork, protects the vehicle from extreme temperatures and aerodynamic forces as it accelerates to more than 17,000 mph in minutes. It also plays a vital role in maintaining the supercooled liquid hydrogen and liquid oxygen propellants—kept at temperatures as low as -423°F—by preventing them from warming and boiling off before launch. Engineered to be both flexible and durable, the third-generation foam can withstand harsh launch conditions while remaining environmentally improved over earlier formulations. Its characteristic orange hue develops over time as ultraviolet exposure from the sun darkens the initially light-yellow material.

Beyond its recognizable orange exterior, the SLS features a complex system of markings that serve both visual identification and critical engineering functions. In addition to national and agency insignia such as the U.S. flag, NASA logos, and the European Space Agency emblem, the rocket and supporting hardware are covered with black-and-white photogrammetric patterns—checkerboards, circles, and squares—used to track motion and orientation during liftoff, ascent, and stage separation. More than 170 of these markings have been carefully sized and positioned across Artemis II to enable engineers to analyze high-speed imagery from onboard, ground, airborne, and ship-based cameras that compares real-world vehicle behavior to predictive models. Additional optical targets support astronaut rendezvous operations, while internal markings—visible only to onboard cameras—capture critical separation events. This extensive imaging and marking system allows engineers to study every phase of flight in detail, refining performance models and improving future mission reliability.