NASA's Artemis II rocket booster stacking process reaches new milestone

The most recent addition is the sixth of the 10 motor segments in the Artemis II Space Launch System rocket to be integrated onto mobile launcher 1 inside the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, according to an update from the space agency's Exploration Ground Systems Program.

Next to be installed will be the left center center segment, which is adorned with the NASA "worm" insignia, they said. Both assemblies were transported to the VAB from the spaceport's Booster Fabrication Facility on Jan. 14.

NASA says forward segments are comprised of three parts: the nose cone that serves as the aerodynamic fairing; a forward skirt that houses avionics; and the frustum that houses motors that separate the boosters from the SLS core stage during flight.

The forward assemblies will be the last segments needed to complete the booster configuration, with assembly of the core stage to follow. The 177-foot-tall twin solid rocket boosters provide more than 75% of the total SLS thrust during liftoff, the agency says.

The timeline for the delay-plagued Artemis moon landing program last month was pushed back to April 2026 from a hoped-for September 2025 launch, while Artemis III -- which is to land the first woman and next man on the moon -- was rescheduled for mid-2027.

The delay came as engineers sought to modify the heat shield on the Orion space capsule after it sustained unexpected damage during re-entry into the Earth's atmosphere in the uncrewed Artemis I mission of 2022.

The stacking operations began in November and are expected to take about four months to complete.

The Artemis II mission is planned to send NASA astronauts Reid Wiseman, Victor Glover, Christina Koch and Jeremy Hansen on a 10-day flight around the moon. It is to be the first crewed flight of the program, as well as the first time people will fly on the SLS rocket and Orion spacecraft.