Amentum, a prominent engineering and technology solutions provider, played a crucial role in the recent Countdown Demonstration Test (CDDT) for NASA's Artemis II mission at the Kennedy Space Center on December 20. The company delivered advanced end-to-end ground systems engineering support for this key launch rehearsal. The CDDT was a comprehensive simulation of launch day operations for the integrated Orion spacecraft and the Space Launch System (SLS) rocket, which is designed to carry four astronauts on an approximately 10-day journey around the Moon. Over 300 Amentum personnel were mobilized for the test, providing support for critical functions including countdown operations, field support, and operating within NASA's Launch Control Center. Their involvement is part of NASA's Exploration Ground Systems (EGS) program, where Amentum is responsible for modernizing ground equipment, integrating launch vehicles, and assisting with overall launch and recovery operations for Orion and the SLS. The Artemis II mission is a historic endeavor, marking the first crewed flight in NASA's Artemis program and the first time humans will venture to the vicinity of the Moon since Apollo 17 in 1972. The mission's primary goal is to confirm that all of the Orion spacecraft's systems function as designed with a crew onboard in the deep space environment. The launch of Artemis II is currently scheduled for no later than April 2026, with potential launch windows opening as early as February 2026. This successful rehearsal is a significant step forward in preparing for this landmark mission, underscoring Amentum's integral contribution to human space exploration.