>This means the space is for
us to feature our special interactive science exhibits
Not quite, it means that in that space we will feature our special interactive science exhibits
Good question, still.
I initially thought that in which just makes everything more clear, but the meaning would not change without it, because you have our and us.
But it's not so, without it:
He has given us a state-of-the art, user-friendy space to feature our special interactive science exhibits.
can be read as:
Our special interactive science exhibits will have as their (main) feature a state-of-the art, user-friendy space.
which is not what you want.