Airbus said Thursday the second European service module will be built to provide propulsion, power and thermal control as well as water and oxygen supply for astronauts during Orion missions beyond the moon.
ESA awarded Airbus a prime contract to develop the first ESM in November 2014.
Airbus has begun to integrate more than 20,000 parts and components for the first ESM flight model in May 2016 and will begin integration for the second flight model in 2018.
Orion is designed to transport humans to destinations beyond the low Earth orbit such as asteroids, moon and Mars.
NASA eyes a 2018 launch of Orion and the Space Launch System rocket in an uncrewed flight test called Exploration Mission 1.
The first crewed mission known as Exploration Mission 2 is scheduled to occur in 2021.