SLS booster segments for Artemis 2 arrive in Florida

The booster segments that will form the two five-segment solid rocket boosters for NASA’s Artemis 2 SLS rocket have arrived in Florida for processing at Kennedy Space Center. Credit: NASA
A journey of more than a million miles began by rail as the solid rocket booster segments for NASA’s Artemis 2 mission made their way to Florida’s Space Coast.
The 10 segments that make up both solid rocket boosters for NASA’s second Space Launch System were shipped together by train, a cross-country trek of some 2,800 miles from Corinne, Utah, to Kennedy Space Center in Florida. The journey started Sept. 19, and was completed the afternoon of Sept. 25.
The two five-segment solid rocket boosters, which collectively generate the majority of the 8.8 million pounds of liftoff thrust for NASA’s Space Launch System, are produced by Northrop Grumman. They are manufactured at the company’s facility in Utah, located just north of Salt Lake City.

The train with the 10 solid rocket booster segments for the Artemis 2 mission makes its way through eastern Kansas Sept. 21. Credit: Derek Richardson / Spaceflight Insider
Each booster segment is loaded with solid propellant. They are about 12 feet wide and 32 feet long, weighing some 180 tons, requiring the use of customized flatcars capable of hauling up to 200 tons of oversized equipment. Two flatcars near the front are climate controlled to keep the two aft segments and nozzles at an optimal temperature of 75 degrees Fahrenheit, according to Union Pacific Railroad in a 2020 press release for the Artemis 1 booster transfer.
Union Pacific said that between each car with booster segments is a buffer boxcar filled with 50,000 pounds of concrete. This is done to distribute weight evenly across the train, help prevent the overloading of infrastructure and improve overall train handling.
The first leg of the route began with Union Pacific from Utah to Memphis, Tennessee, where Norfolk Southern Railway took over transportation to Jacksonville, Florida.
In Jacksonville, Florida East Coast Railway took the SRB train to Titusville where the NASA Railroad took possession to transport the cars across the Indian River to Kennedy Space Center for booster processing for the Artemis 2 mission.
NASA is expected to begin stacking the boosters in the cavernous Vehicle Assembly Building early next year atop the SLS Mobile Launcher. Once each 177-foot-tall booster is complete, the Boeing-built SLS core stage will be added.

Union Pacific locomotive No. 1943 “The Spirit” leads the train carrying NASA’s SRBs during the Union Pacific portion of the trek. Credit: Derek Richardson / Spaceflight Insider
The core stage of the SLS rocket is currently at NASA’s Michoud Assembly Facility in New Orleans. Its four RS-25 engines and related hardware are in the process of being attached. Once complete, it will be shipped to Kennedy Space Center by the Pegasus Barge via the Gulf of Mexico and Atlantic Ocean.
All remaining components of the SLS rocket for Artemis 2 — the Interim Cryogenic Propellant Stage, the Launch Vehicle Stage Adapter, and the elements of the Orion spacecraft — are at Kennedy Space Center.
Artemis 2 is expected to launch no earlier than late 2024, possibly early 2025. This 10-day test mission will see the Orion spacecraft with NASA astronauts Reid Wiseman, Victor Glover, Christina Koch and Canadian Space Agency astronaut Jeremy Hansen fly around the Moon on a free-return trajectory before returning to Earth. After a journey of some 1.4 million miles, the capsule and crew will reenter the atmosphere before performing a parachute-assisted splashdown in the Pacific Ocean.
The two five-segment solid rocket boosters will only be needed for the first 126 seconds of the mission. At that point they will fall away into the Atlantic Ocean.
Artemis 2 will be the first human mission to the Moon since Apollo 17 in 1972. It will be followed a year or two later by the Artemis 3 mission, which is currently expected to see the first crewed Moon landing of the 21st century. The first uncrewed test of the SLS-Orion system, Artemis 1, occurred in late 2022.
Video of the SRB train passing Lawrence, Kansas, between Topeka and Kansas City, Missouri. Courtesy of Orbital Velocity.
Derek Richardson
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.