In High Bay 3 of the Vehicle Assembly Building at NASA’s Kennedy Space Center in Florida, the left-hand center center booster segment for Artemis I is lowered onto the center aft booster segment on the mobile launcher for the Space Launch System (SLS) on Jan. 21, 2021. Workers with Exploration Ground Systems and contractor Jacobs teams will stack the twin five-segment boosters on the mobile launcher in High Bay 3 over a number of weeks. When the core stage arrives, it will join the boosters on the mobile launcher, 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. The SLS is managed by Marshall Space Flight Center in Huntsville, Alabama. Under the Artemis program, NASA will land the first woman and the next man on the Moon by 2024. 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.