When Artemis II carries astronauts beyond Earth orbit for the first time in 50 years, Europe will provide the power to make the journey possible. Built by European industry, ESA’s European Service Module (ESM) serves as the propulsion heart of the Orion spacecraft, carrying 33 engines that steer and propel the crew safely to the Moon and back.
Three Engine Types
The ESM features three types of engines, each with a specific role. A single main engine delivers the major thrust needed to send Orion toward the Moon. Eight auxiliary engines handle orbital corrections and can back up the main engine if needed. For precise control, 24 smaller reaction control system engines—arranged in six pods—rotate and orient the spacecraft, allowing Orion to adjust its position with exceptional accuracy.
The main engine is a repurposed Space Shuttle orbital manoeuvring system engine that flew on six missions between 2000 and 2002. Now fully tested and integrated into Orion, it brings proven performance to a new era of exploration.
The Mission
Artemis II will put these engines to work almost immediately after launch. On the first day, Orion remains in Earth orbit while the crew checks systems. After separating from the rocket’s upper stage, astronauts will manually use the reaction control engines to practise proximity operations—docking manoeuvres essential for future Artemis missions.
On the second day, the ESM’s main engine ignites for the trans-lunar injection burn, accelerating Orion out of Earth orbit and sending the crew on a four-day journey toward the Moon. Throughout the flight, additional engine firings fine-tune Orion’s trajectory to keep the spacecraft precisely on course.
European Expertise
These complex operations rely on European expertise on both sides of the Atlantic. Engineers at ESA’s ESTEC in the Netherlands work alongside colleagues in the Mission Evaluation Room at NASA’s Johnson Space Center in Houston, monitoring the ESM around the clock.
Artemis II is the second mission to fly with a European Service Module. The first performed above expectations on the uncrewed Artemis I mission, highlighting the value of Europe’s contribution. With the third and fourth ESM units already delivered and undergoing testing for future missions, Europe continues to deliver the hardware that brings humankind safely to the Moon and back home.
