NASA Artemis II is an engineering-focused guide to the mission design, spacecraft architecture, and economic logic behind NASA’s return to the Moon. Artemis is not simply Apollo repeated. It is a modern lunar programme shaped by new safety expectations, distributed mission architecture, commercial partnerships, orbital constraints, industrial realities, and long-term ambitions beyond a single landing. This book uses Artemis II as the central case study to explain how modern crewed lunar missions actually work. Rather than focusing only on what happens during the mission, it explores why the architecture is designed the way it is: why vehicles are staged, why abort paths matter, why lunar orbits are chosen for stability and operations, and why every engineering decision creates consequences elsewhere in the system. Readers will explore SLS, Orion, translunar injection, free-return logic, deep-space crew safety, life support, re-entry physics, Gateway, NRHO, Human Landing Systems, mission economics, and the engineering trade-offs that define the Artemis programme. Written for engineers, students, space enthusiasts, and technically curious readers, NASA Artemis II provides a clear and grounded explanation of humanity’s return to the Moon—and what it takes to make that return sustainable.