In a significant milestone towards NASA's Artemis II mission, the core stage of the agency's second Space Launch System (SLS) rocket has arrived at Kennedy Space Center in Florida. The arrival of the core stage marks an important step in the preparation for the mission, set to be the first human voyage to the vicinity of the Moon since 1972.

The Artemis II mission, scheduled for September 2025, will carry a team of four astronauts, including NASA astronauts Reid Wiseman, Victor Glover, Christina Koch, and Canadian mission specialist Jeremy Hansen. Their journey will begin by riding the SLS rocket away from Earth, flying around the far side of the Moon, and returning home inside NASA's Orion spacecraft.

Matthew Ramsey, NASA's mission manager for Artemis II, emphasized the significance of the core stage, calling it "the backbone" of both the SLS and the Artemis mission. With the arrival of the core stage, integrated tests and checkouts can now be conducted, as it contains the flight avionics that drive the entire system.

The core stage, transported via NASA's Pegasus barge from New Orleans, where Boeing builds the rocket under contract to NASA, rolled off at Kennedy Space Center early Wednesday. The next step in the process involves stacking the two powerful solid rocket boosters on NASA's mobile launcher platform, a crucial operation that is anticipated to commence in September. Both boosters, supplied by Northrop Grumman, consist of five segments with pre-packed solid propellant and a nose cone.

The SLS upper stage, constructed by United Launch Alliance, is already at the Florida launch site, while the remaining elements of the SLS rocket, including the adapter structures connecting the core stage to the upper stage and the upper stage to the Orion spacecraft, are scheduled to be delivered in August or September.

Ground teams at Kennedy Space Center will utilize a heavy-duty crane housed in the Vehicle Assembly Building (VAB) to assemble the SLS boosters on the launch platform. Once the boosters are fully stacked, the 212-foot (65-meter) core stage will be vertically lifted in the transfer aisle within the VAB and carefully lowered between the boosters, a step expected to take place as soon as December.

Following the core stage, other components, such as the launch vehicle stage adapter, the upper stage, the Orion stage adapter, and ultimately, the Orion spacecraft itself, will be integrated into the SLS rocket.

The Artemis program has been met with financial scrutiny, with NASA's inspector general reporting in 2022 that each of the first four Artemis missions will cost $4.1 billion, with the expendable SLS core stage accounting for a significant portion of the expenses. Nevertheless, NASA remains committed to the mission's objectives and continues to work towards its success.

The core stage for Artemis II will be powered by four hydrogen-fueled RS-25 engines, manufactured by Aerojet Rocketdyne, two of which have already flown on the space shuttle. While there are no major configuration differences between the core stages for Artemis I and Artemis II, minor adjustments have been made based on flight observations from the test flight of Artemis I.

As preparations for the historic Artemis II mission continue, NASA's focus remains on ensuring the success of the mission and expanding our knowledge of our celestial neighbor, the Moon.