### Instruction:

Extract the cause and effect entities from the following sentence:
The Orion spacecraft will bring crews to the Gateway and return them to Earth once the mission is completed

### Assistant:

CAUSE_1: the mission is completed
EFFECT_1: The Orion spacecraft will bring crews to the Gateway
EFFECT_2: return them to Earth
VARIABLE: The Orion spacecraft
CONDITION: return them to Earth
KEYWORD: once
AND: and

