Airbus ships the third European Service Module to Cape Canaveral on behalf of ESA

Bremen, 22 August 2024 - Orion’s third European Service Module (ESM-3) is leaving Airbus’ facilities in Bremen, Germany, and heading to NASA’s Kennedy Space Center in Florida, USA, where it will be assembled and tested with the Crew Module. This third mission of NASA’s Artemis programme will mark the first human return to the lunar surface since Apollo 17 in 1972.

ESM-3, built by Airbus under contract to the European Space Agency (ESA), will play a critical role in supporting four astronauts during their three-week mission aboard the Orion spacecraft: from the moment they leave Earth, their journey into lunar orbit, docking with the lunar landing system Starship HLS, and their safe return to Earth.

Ralf Zimmermann, Head of Space Exploration at Airbus, said: “Today’s delivery of the third ESM marks the beginning of yearly ESM deliveries, underlining the importance and reliability of Europe in this transatlantic partnership.” Airbus Defence and Space is under contract up to ESM-6 and long lead items procurement up to ESM-9.

ESM-3 ready for shipment — ESM-3 ready for departure © Airbus DS

Space is an incredibly harsh environment with temperatures dipping as low as -200°C. To keep the astronauts safe and comfortable Airbus has developed comprehensive thermal energy control systems to keep the crew module between 18 and 24°C by radiating excess heat out of the ship but also keeping the cold at bay.

In addition, the ESM provides essential elements to the astronauts during their trip to and from the Moon, "NASA asked us to create a standard atmosphere similar to Earth, which means we have to add nitrogen to the cabin. The ESM carries 90 kilogrammes of oxygen and 30 kilogrammes of nitrogen. We also use the nitrogen to pump drinking water from the 240 litre tank for the astronauts,” said Zimmermann.

Unlike the Apollo missions, which used fuel cells to generate electricity, Orion uses only solar arrays. The four wings generate 11.2 kW of power per hour, enough to power two four-person households on Earth. Only about 10% of the power is needed for the ESM, with the remaining 90% going to the batteries and equipment in the crew module. The Artemis I mission highlighted that the solar panels were able to produce a bit more power than expected, it will be useful to have this additional energy available as the Artemis programme evolves.

The energy stored in the batteries is key as it ensures that the Orion spacecraft has power even when the Sun is obscured. The batteries also provide power for a safe return when the ESM separates from the crew module at the end of the mission, at which point it will lose access to the solar panels, the only source of power.

To enable astronauts to concentrate on the most important tasks, the avionics onboard the ESM provide a very high level of autonomy, such as temperature regulation and solar wing rotation to track the Sun. In principle, the whole spacecraft can fly the mission completely autonomously, but compared to the uncrewed Artemis I mission, Artemis III will require the astronauts to dock manually with the landing system Starship.

Orion has 33 engines onboard the ESM to provide thrust and manoeuvring capabilities. The main engine, a repurposed Space Shuttle orbital manoeuvring system engine (OMS-E) provided by NASA, generates 26.5 kilonewtons of thrust. This provides enough force to escape Earth’s gravitational field and perform the translunar injection burn, to get into the Moon’s orbit. Eight auxiliary thrusters act as back-ups to the OMS-E and for orbital corrections. There are also 24 smaller engines for attitude control in space, enabling the spacecraft to rotate or change its angle during docking manoeuvres.