ESM meaning in Regional ?

The European Service Module (ESM) is the service module component of the Orion spacecraft, serving as its primary power and propulsion component until it is discarded at the end of each mission. In January 2013, NASA announced that the European Space Agency (ESA) will contribute the service module for Artemis 1, based on the ESA's Automated Transfer Vehicle (ATV). It was delivered by Airbus Defence and Space in Bremen, in northern Germany to NASA at the end of 2018. After approval of the first module, the ESA will provide the ESMs from Artemis 2 to Artemis 6.

The service module supports the crew module from launch through separation prior to reentry. It provides in-space propulsion capability for orbital transfer, attitude control, and high altitude ascent aborts. It provides the water and oxygen needed for a habitable environment, generates and stores electrical power, and maintains the temperature of the vehicle's systems and components. This module can also transport unpressurized cargo and scientific payloads.