Amentum's Ground Systems Engineering Proves Critical in Artemis II Launch Rehearsal

CHANTILLY, VA – December 29, 2025 – In a pivotal step toward returning humans to the vicinity of the Moon, a comprehensive launch day simulation for NASA's Artemis II mission was successfully completed at the Kennedy Space Center. The success of this Countdown Demonstration Test (CDDT), held on December 20, relied heavily on the advanced ground systems engineering provided by Amentum, a global technology and engineering firm.

The rehearsal was a full-scale, end-to-end simulation of the procedures for launching the integrated Orion spacecraft and the powerful Space Launch System (SLS) rocket. This test represents a critical milestone for the Artemis II mission, which is slated to carry four astronauts on an approximately 10-day journey around the Moon and back, marking the first crewed lunar flyby in over half a century. The successful execution of the CDDT validates the complex interplay of hardware, software, and human teams essential for a safe and successful launch.

The Backbone of the Countdown

Behind the towering rocket and sophisticated spacecraft lies a less visible but equally vital network of ground systems and personnel. Under NASA’s Exploration Ground Systems (EGS) program, Amentum is tasked with the monumental job of ensuring this terrestrial foundation is flawless. The company’s role encompasses modernizing ground equipment, meticulously integrating the launch vehicle components, and assisting with overall operations for both the Orion spacecraft and the SLS rocket.

During the December 20th rehearsal, Amentum mobilized a team of more than 300 engineers, technicians, and support staff. These personnel were deployed across a range of critical functions, from hands-on field support on the launch pad to high-stakes decision-making roles within the Firing Room at NASA’s Launch Control Center. It is from this fabled room that engineers conduct final pre-launch checks, monitor thousands of systems parameters, and issue the commands that bring the rocket and spacecraft to life.

Amentum’s contribution was also central to the operation of the Launch Control System (LCS), the sophisticated software that serves as the digital backbone of the Firing Room. This system is responsible for processing immense volumes of real-time data, enabling remote command and control of the vehicle, and recording every detail throughout the test. The LCS ensures that every phase of integrated testing and the final launch countdown is conducted safely and efficiently, providing the mission control team with the critical information needed to manage the launch sequence.

Integrating Giants for a Historic Journey

The Artemis II mission is powered by the Space Launch System, the most powerful and capable rocket NASA has ever constructed. Perched atop this behemoth is the Orion crew module, a spacecraft designed to sustain astronauts on long-duration missions in deep space. Bringing these two colossal and highly complex systems together into a single, functional launch vehicle is a feat of engineering integration.

Amentum played a direct and crucial role in this process during the CDDT. The company’s engineers were responsible for the configuration and systems performance of the crew module during the full vehicle power-up, a key phase of the simulation where the entire integrated stack is activated. This involved verifying that all of Orion’s systems were communicating correctly with the ground systems and the SLS rocket, a fundamental check to ensure the vehicle is ready for its journey.

“As the first crewed mission on NASA's path to establishing a long-term presence on the Moon, Artemis II represents a groundbreaking step in human space exploration,” said Mark Walter, Amentum’s president of Engineering & Technology, in a statement. The successful rehearsal, he noted, highlights the company's deep expertise in high-consequence launch operations.

A Critical Milestone on the Path to Deep Space

For missions of this magnitude, rehearsals are not mere practice runs; they are essential for mitigating risk. The CDDT allows the entire launch team, from NASA and its commercial partners, to walk through every step of the countdown, identify potential issues, and refine procedures in a controlled environment. Every problem solved on the ground is one that does not threaten the safety of the crew in space.

Walter emphasized this point, stating, “The successful execution of the Countdown Demonstration Test highlights the depth and breadth of Amentum’s capabilities, including launch vehicle integration, spacecraft processing, and ground systems engineering. With this critical milestone we continue to demonstrate our commitment to excellence in high consequence launch operations.”

The Artemis program's ambition extends far beyond a single lunar flyby. It aims to build a sustainable human presence on and around the Moon, creating a stepping stone for eventual missions to Mars. Artemis II is the crucial next phase following the uncrewed Artemis I test flight, designed to push the Orion spacecraft to its limits and prove its life-support, communication, and navigation systems are ready for human occupants.

With the successful CDDT now complete, NASA and its partners are one significant step closer to the planned launch of Artemis II, which is expected no later than April 2026. The data gathered from this test will be meticulously analyzed to fine-tune operations for the historic launch day, ensuring that when the four astronauts board the Orion capsule, the teams and technology on the ground are prepared for every contingency.