On 2 April 2026, at 00:24 UTC, NASA launched the Space Launch System (SLS) from the Kennedy Space Center as part of its Artemis II mission, marking the first crewed flight to lunar orbit since the Apollo missions. The mission aims to test the Orion spacecraft and the SLS rocket in deep space, perform a flyby of the Moon, and demonstrate proximity operations with the Interim Cryogenic Propulsion Stage (ICPS).1 Artemis II is part of a long-term strategy to return sustainably to the Moon and prepares for future crewed missions to Mars, while relying on international cooperation through the European Service Module developed by ESA.2

The SLS forms the technical core of this mission. The rocket combines four RS-25 liquid-fueled engines with two five-segment solid rocket boosters inherited from the Space Shuttle, producing a maximum thrust of 8,8 million pounds (= 39,144 kN). The boosters provide thrust for the initial two minutes, while the RS-25 engines propel the vehicle for eight minutes to reach Earth orbit. The SLS architecture includes several critical subsystems, such as propellant supply, pressurization, main propulsion, and pre-launch pneumatics, with industrial shared responsibilities: Boeing for the core stage and ICPS, L3Harris for the RS-25 engines, Northrop Grumman for the boosters, and Teledyne Brown Engineering for the launch vehicle adapter.

Despite its performance, the SLS faces significant economic and management challenges. The NASA Office of Inspector General report (2023) notes cost overruns of approximately $6 billion and over six years of delays on certain engine and booster contracts.3 These issues highlight the programme’s complexity and the rigor required to integrate all critical systems. Nevertheless, the SLS currently remains the only operational solution capable of sending astronauts directly around the Moon, providing a level of reliability that commercial launchers in development have not yet achieved.4