A crane slowly moves the European Service Module (ESM) for NASA’s Artemis II mission into the FAST (final assembly and system testing) cell inside the high bay of the Neil A. Armstrong Operations and Checkout Building at NASA’s Kennedy Space Center in Florida on May 22, 2023. Teams from NASA and Lockheed Martin are transferring the service module to the FAST cell for final checkouts before it is stacked with the Orion crew module.. The powerhouse that will fuel and propel Orion in space, the ESM will be used for Artemis II, the first Artemis mission flying crew aboard Orion.