There is no permanent dark side of the moon. There is a near side we can see and a far side we can’t, but any point gets two weeks of sun and two weeks of darkness.
“There is no dark side
of the moon really.
Matter of fact
it’s all dark.”
Pink Floyd.
Obviously you are incorrect. The Moon is flat and only has two sides. One is always dark. /s
Of course there is no ‘dark side’ of the moon.
It’s all dark!
And, compared to space, it is a terrible place for a telescope.
A major telescope is a large, very precise instrument. The temperature changes associated with going from full sun to full shade make any telescope very hard to design and very expensive compared to the uniform environment of space.