Space Launch System: One Step Closer to the Moon—and Beyond

by

With the successful launch of Artemis I and the second SLS rocket nearing completion, aerospace experts engage the next generation, assuring them that this is just the beginning of a long and mind-blowing highway into deep space.

Every day, Amanda Swanson, a Space Launch System (SLS) propulsion engineer at Boeing, takes her husky mix Riley to a dog park outside her apartment in Orlando, about 45 minutes from Kennedy Space Center. Often, she runs into a precocious fifth-grader with bangs and glasses who likes to talk to Swanson about her love of math and science. Shortly before the first launch attempt for Artemis I, in August, the girl approached Swanson and said, “Did you know that the most powerful rocket ever is going to launch in a few days? It’s called Artemis, and it’s going to eventually take the first woman to the Moon!”

When Swanson told this story recently, she was still riding high from the Artemis launch at Kennedy Space Center on November 16 and was as excited as, well, a fifth-grader. She said she told her young friend that she had worked on building that rocket and showed her pictures on her phone, much to the girl’s delight. “It’s really cool to show the younger generation that this is possible,” Swanson said. “I told her, ‘Keep pursuing your dreams. We’re going to the Moon and hopefully going to Mars after that. You can be part of it.’”

Since astronauts last walked on the lunar surface more than 50 years ago, humans have dreamed about returning to the Moon, setting up a base there and traveling beyond. With the November launch of Artemis I, an uncrewed Orion spacecraft atop SLS—the most powerful rocket in the world—the United States is one important step closer to the day when deep space exploration becomes a reality.

“The Artemis I mission was a thrilling success, and people around the world got to see the capabilities of the rocket,” said John Shannon, Boeing vice president and SLS program manager, an industry veteran who had been dreaming about this moment since the Apollo program ended when he was 7 years old. “But equally exciting to me is that this is not a one-shot-mission. It’s building a factory, team and supply chain that is able to put together that success over and over and over again.”

The Artemis Generation

Aptly named for the twin sister of Apollo, Artemis—the goddess of the Moon in Greek mythology—is the series of deep-space missions that will pave our way to the lunar surface—and far past it. These missions will land the first woman and first person of color on the Moon, which is nearly 1,000 times farther than where NASA’s International Space Station resides in low-Earth orbit. Artemis will establish the first long-term human-robotic presence on and around the Moon: Artemis Base Camp, comprised of a modern lunar cabin, a rover and a mobile home; and Gateway, a spaceship that will support lunar science and exploration. Eventually, Artemis will send the first astronauts to Mars, 140 million miles away. The dedication, hard work, passion and excitement required to make these missions a reality in the coming decades falls largely on the shoulders of young enthusiasts from all walks of life. They have been nicknamed, of course, the Artemis Generation.

“The Apollo program was defining for earlier generations,” said Swanson, who spent her own childhood gazing at the stars. “And being a part of Artemis, which will define future generations, is incredibly exciting.”

As a grade schooler, Swanson earned her Girl Scout astronomy badge and wrote a letter to NASA explaining why she would make the perfect astronaut. In high school, she led a team to design and build a human-powered lunar rover for NASA’s Great Moonbuggy Race, and in college, she met a Boeing engineer who told her about SLS—after which her path became crystal clear.

In the last five years at Boeing, she’s transitioned from a design engineer to a production task lead to launch team support. As she’s followed the core stage vehicle from Alabama to Louisiana to Mississippi to Florida, she’s gone from being the only woman in meeting rooms to part of a majority in those same rooms—which makes her even more excited about being a role model for future generations.

“I hope to see this trend continue into the future, as we set the example for young girls that they can do anything they set their minds to,” she said. “Representation matters to young minds, which is why the message of the Artemis mission is so important. You never know when you might be the next Katherine Johnson or Sally Ride to inspire the next generation.”

November’s Artemis launch was packed with superlatives: Orion sat atop the most powerful rocket in the world; on its 25-day mission around the Moon and back, it flew farther than any spacecraft built for humans has ever flown; it stayed in space longer than any human spacecraft ever has, without docking to a space station; and it returned home faster and encountered hotter temperatures than any of its predecessors.

But for those who saw it live, at 1:47 a.m., the most enduring image was that of this super heavy-lift vehicle—with its 212-foot-long core stage and its massive orange flame—instantly turning night into day. From miles away, spectators shielded their eyes from the blinding light and felt vibrations in their chests. They cheered, clapped, hugged and cried. Even for launch veterans, the moment was filled with emotion.

“What stood out to me was how bright and powerful it was,” said Wes Adams, Boeing’s propulsion integration and test lead for Artemis II—the first crewed flight. “We know that classic shot of Saturn V clearing the tower,” he said about NASA’s last exploration-class rocket built for human space travel, 50 years ago. “But to see that happen in person—and to feel it. That was unlike anything I’ve ever experienced before.”

“I was overcome with emotion,” said Sarah Harden, a liaison engineer for Boeing who was responsible for resolving nonconformances on Core Stage 1. She watched the launch from a few miles away and said despite seeing launches regularly, this one felt different. “It was so many years of hard work, overtime, weekends and continuous improvement to get to where we were. To be able to see that pay off in the most epic way possible, so many parts working together, was incredible. And it went off without a hitch.”

Harden has wanted to be part of the space program since she was a child in Minnesota, and her resolve only strengthened after watching the tragic Space Shuttle Challenger explosion in 1986. “My generation wasn’t around for the last moonwalk, so I’m particularly excited to see a long-term presence on the Moon in my lifetime,” she said. “The launch wasn’t just our project. We’ll be able to improve life for all people on Earth with the research and advancements we develop on the Moon and Mars. This is really for all of humanity.”

Kristine Ramos, Boeing’s business development lead for SLS and Science Mission Directorate, said she’s endlessly amazed by the potential of SLS—which she suspects the public doesn’t yet fully appreciate.

Built by Boeing, the lead contractor for the design, development, test and production of the SLS core stage and,ICPS (Interim Cryogenic Propulsion Stage), the family of rocket variants will fly for generations to deep space destinations, evolving into increasingly more powerful configurations. The fourth Artemis mission, for example, will fly with a much more powerful Exploration Upper Stage (EUS) instead of an ICPS. That extra power will give SLS a lifting capacity of 42 tons beyond Earth orbit in a single launch. That is a powerful reach no other rocket is even planned to match without a lot of refueling along the way.

SLS stores cryogenic liquid hydrogen, liquid oxygen and all the systems that feed the stage’s four R-25 engines, as well as the flight computers and avionics needed to control the rocket’s flight. Future vehicles will be able to carry, in a single launch, an Orion crew vehicle along with large cargos for exploration systems needed to support a sustained presence on the Moon, Mars and other deep space destinations. These missions will reach their destinations faster than previously possible and will open up new orbits and trajectories for missions that require both human-occupied spacecraft and heavy cargo including huge, fully assembled infrastructure such as orbiters, landers and rovers.

“We haven’t even skimmed the surface yet with SLS,” said Ramos, who recently celebrated a decade at Boeing. “Once we see what this vehicle is capable of, where else can we go?” She hopes people from all professional backgrounds who watched the launch are inspired—engineers, of course, but also those who work in food, textiles, law, medicine and other fields that will one day benefit from what we learn in deep space.

The key now, Ramos said, is getting the word out to other companies, other countries and academia, explaining why Artemis is important and sustainable. “Now that we’ve launched, I think we need to educate the public,” Ramos said. “Look what we can do with this rocket! Look what’s going to happen in your lifetime! We gave you the first rocket; now we need missions. We’re waiting for everyone else to catch up!”

Many communities are looking for a heavy-lift vehicle to enable a host of new mission opportunities, including delivering landers to explore Jupiter’s moon Europa; sampling geysers of Saturn’s moon Enceladus; exploring the liquid hydrocarbon lakes of Saturn’s moon Titan; finding habitable planets using large-diameter, space-based telescopes; and launching solar power plants. SLS can also support planetary defense missions such as redirecting an Earth-threatening asteroid and broader research in heliophysics, interstellar space and the origins of the universe. For all these missions and more, SLS serves as the anchor point for other partners.

“Those communities are all looking to put a science mission on a rocket, and they need support from SLS,” Ramos said. She noted that the SLS can not only lift very large probes off Earth but get them moving so fast they can reach their destination in a fraction of the time of conventional rockets; a six-year-journey to Jupiter becomes two-and-a-half years, which means the spacecraft gets there faster and returns data years sooner.

When Voyager launched in the 1970s, it took more than 30 years for it to reach interstellar space—the first time a human-made object has done so. “Sometimes that’s not in the lifetime of the principal investigator,” Ramos said. “With SLS, we’ll be able to get there in 13 or 14 years. What we learn during that time from other planets can change our lives.”

Accomplishing hard things—as a company, as a country

The November launch marked the culmination of a decade of development, engineering, production and manufacturing. That decade also included setbacks such as a global pandemic, hurricanes, technical issues, supply chain delays and moves to different production locations. In 2020 alone, Michoud Assembly Facility in New Orleans witnessed six major weather events. Yet by launch day in November, NASA and Boeing had completed millions of flight software simulation tests—the complete battery of tests initially planned.

“Our teams always push through with new ideas and pull in fresh perspectives from across Boeing, as well as our supply chain,” said Shannon. “Innovation is how we’ve beaten both technical and schedule challenges.” He said when people ask him if he was surprised that everything worked perfectly at the launch, his answer is always the same: “If anyone could see the engineering rigor in our test plans for SLS, there was very little doubt this wouldn’t work exactly as designed,” he said. “We’re thrilled with the performance but not surprised.”

Now that Boeing knows its rocket design is solid, the SLS team is turning its attention back to production and assembly activities for future Artemis missions, implementing lessons learned about the factory setup, tools and processes.

“The very first time the vehicle was built, we faced a lot of challenges,” Swanson said. “A component can look perfect on paper, but then you have to do live problem solving, come up with solutions to get through different issues, make tweaks and adjustments and see the culmination.” She said she learned a lot from the first mission about building processes and how to streamline. “It’ll be exciting seeing it all come together quickly in future missions, as we get to a more frequent launch cadence.”

Already, Boeing has begun streamlining processes and reducing costs through bulk purchases from suppliers. At the beginning, for example, workers drilled holes in some of the large beams during assembly., said Adams, who joined the propulsion team after college in 2017, having been inspired as a child by astronaut Robert Curbeam. Shifting the drilling of these structural components they arrive on site already, Adams said, has saved months.

In some cases, the test launch informed Boeing that they could make some tweaks and reduce redundancies in future vehicles. For instance, engineers included a tremendous number of heaters in Artemis I to protect components from the cryogenic environment, Shannon explained, and they later realized some of those heaters aren’t required. Removing some of them will help trim overall costs.

As the SLS program transitions from rocket development efforts to operations, Boeing has also worked with NASA to increase efficiency and optimize space at 70-year-old Michoud, moving some of the assembly to Kennedy Space Center. This shift, overseen by Swanson enables the workforce at Michoud to begin building the first EUS, the powerful upper stage that boasts massive propellant tanks and four engines to speed payloads far beyond Earth.

All major core stage structures will continue to be manufactured at Michoud (where the Saturn V stages were built) using state-of-the-art manufacturing equipment, including a friction-stir welding tool that is the largest of its kind in the world. Beginning with Artemis III, these core stages will be shipped to Kennedy’s Vehicle Assembly Building for final engine assembly and integration. To date, four of five major core stage parts for Artemis II have been joined, and teams will soon connect the engines to complete the stage at Michoud before it’s delivered to Kennedy in 2023. Core Stages 3, 4 and 5 are in various stages of construction, and parts for Core Stage 6 are already being delivered.

As the Apollo program did decades ago, Artemis will bring together players in the aerospace industry. SLS emerged from a collaboration between 1,100 contractors in more than 45 states, a team of Space Shuttle veterans with decades of hands-on experience and aerospace novices who are aces at 3-D printing and CAD modeling.

Shannon said a number of companies that worked on the Space Shuttle program have re-joined the space systems supply chain, benefiting the entire industry as they renew their certifications and re-establish their own talent and supply chains.

“American small businesses are literally providing the nuts and bolts of NASA’s space systems,” said Shannon. “By leading the way, NASA provides the stability necessary to rebuild a competitive space industry. It’s hands-down one of the best investments in American manufacturing.”

The space industry is also one that historically unites Americans—from all backgrounds and from both sides of the aisle, Shannon said.

“There’s no political angle on anything Artemis is doing,” he said. “It brings unity and a sense of pride that we’re still capable of doing hard things as a country.”

Today, that hard work means building the Gateway space station around the Moon.

“It’s the first link of a long chain of space exploration,” Shannon said. These days, when he walks outside at night, he looks at the Moon differently. “I know there’s now a crew-capable spacecraft that can get us there,” he said. “And in two years we’re going to have a crew that will be in orbit around it. I’ve been in the space business for 35 years, and it still blows my mind.”

Days after the Artemis I launch, when stunning photos came back from Orion showing the Earth and Moon together, hanging in the blackness of space, Shannon shared them with his 16-year-old daughter.

“She was blown away,” Shannon said. He told her that this was just a first step, that she and her siblings will have the opportunity to walk on the Moon one day. “To get a 16-year-old to get that perspective of where we are in space, how small and fragile the planet is—you’ve really done something.”