SEE not infer.

The technology does not use glass lenses nor reflective mirrors but an advanced form of a pinhole camera, the "pinhole" technique is called Fresnel zone plates.

New Scientist article.

The technical hurdles would be tricky but nothing unbelievable.

Essentially we would need to launch two spacecraft.: one is the "lens" and one is the "receptor".  The focal point using the Fresnel method is kilometers away from the lense, ergo the two spacecraft solution.

Go read the whole article, just fascinating.

Feeds right into this post: Planet Hunting, The Next Generation - The Lyot Project