Don't say:
The astronauts are bringing plants to the moon.

Say:
The astronauts are taking plants to the moon.

Note:
To fetch means to go somewhere else and come back with something: Please fetch me a glass of water (= go and come back with a glass of water). Using bring or take depends on where the speaker or doer is. We use bring for things coming to where we are and take for things going somewhere else: Take these cakes to your grandmother and bring (back) some flowers from her garden.