In High Bay 3 of the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, right-hand and left-hand forward segments are secured on top of the center forward segments on the mobile launcher (ML) for the Space Launch System (SLS) on March 3, 2021. Workers with Exploration Ground Systems and contractor Jacobs teams completed the stacking of the boosters over several weeks. When the core stage arrives, it will join the boosters on the ML, followed by the interim cryogenic propulsion stage and Orion spacecraft. Manufactured by Northrop Grumman in Utah, the twin boosters provide more than 75 percent of the total SLS thrust at launch. Marshall Space Flight Center in Huntsville, Alabama, manages the SLS. Under the Artemis program, NASA will land the first woman and the next man on the Moon. The first in a series of increasingly complex missions, Artemis I will test the Orion spacecraft and SLS as an integrated system ahead of crewed flights to the Moon.