The AJ10-190 produces 26.7 kN (6,000 lbf) of thrust and is refurbished from Space Shuttle Orbital Manoeuvring System (OMS) engines — a proven design with hundreds of flights of heritage. It performs every major velocity change: perigee raise, apogee raise, Trans-Lunar Injection, return trajectory corrections, and attitude maintenance throughout the mission. When the engine fires, it is the only propulsion system keeping the crew on course for the Moon.
8 auxiliary thrusters (490 N each) support smaller manoeuvres and redundant propulsion. 24 attitude control thrusters (220 N each) maintain Orion's precise orientation throughout the 10-day mission — pointing solar arrays at the Sun, antennas at Earth, and the heat shield in the right direction for re-entry.
Four deployable solar array wings span 19 metres when fully extended — roughly the width of a tennis court. Each wing carries ~15,000 triple-junction gallium arsenide solar cells generating a combined 11.1 kW of continuous power to run Orion's computers, communications, life support, and heating systems. The arrays rotate to track the Sun regardless of spacecraft orientation.
The ESM carries the consumables the crew depends on for survival: water in four tanks (~125 lbs each), oxygen, and nitrogen for cabin pressure. These are transferred through umbilicals into the crew module as needed throughout the mission. The ESM also manages thermal control — regulating temperatures across Orion's systems in an environment that swings between -157°C in shadow and +120°C in direct sunlight.
The ESM is a pan-European engineering achievement. Airbus leads integration in Bremen, Germany, but components come from 13 ESA member states: the solar arrays from the Netherlands, propellant tanks from France, the structural cone from Spain, electrical harnesses from Switzerland, and more. The ESM represents the largest European hardware contribution to human exploration beyond low Earth orbit.
ESA's "Eagle Room" at ESTEC in Noordwijk, Netherlands, monitors ESM telemetry 24 hours a day throughout the mission. Dedicated console positions cover propulsion, avionics, thermal, electrical power, and safety. ESA's Mission Evaluation Room team — part of more than 200 specialists supporting Artemis II — works in close coordination with NASA and Lockheed Martin engineers at Johnson Space Center in Houston.
ESA's EveryWear app, developed by MEDES and CNES in France, was adapted from its ISS iPad version to run on Orion's Windows-based systems. During Artemis II it allows the crew to log nutrition intake, medications, and medical questionnaires, and communicate securely with flight surgeons on the ground — extending ISS-quality medical monitoring into deep space for the first time.