Which one is wrong?

It is said that no potential frontier has so fired the imagination or challenged the ingenuity of humankind as space has.

That's how I'd say it!

More interesting is why you think "such" is wrong here. I would say it isn't. This seems like a perfectly good sentence to me.

"It is said that no potential frontier has such fired the imagination or challenged the ingenuity of humankind as has space."

No problems with that.
Rommie

but there should be one mistake in this sentence. It is a question from Educational testing service. I thought "such" is wrong because as far as I know such can be used:

such as
such a diligent student that

What is the pupose of such in this sentence?

Besides, why is the sentence ended with as has space? I think as space has is more appropriate. Unfortunately I

I can think of three possibilities - pretty much the same one's you've thought of:

1. "such" should be "so"
2. the last "has" is superfluous
3. "space" should be "that of space"

You're probably right about "such". I think maybe it's supposed to be "so". I guess I'm just used to hearing it said incorrectly.

I also concur that the last "has" may be superfluou

It is said that no potential frontier has such fired the imagination or challenged the ingenuity of humankind as has space.

unfortunately I don't have chance to get the answer of this question.

I am confused in one point. is "has" a possession or does it indicate perfect tense?

the such certainly sounds wrong to me!