So how much do you really know about movies? Give me $30 billion and I'll fake it. Watch 2001: A Space Odyssey.
Which part?
Do you mean the part where the Earth is lit from the wrong side, is too large, and is in the wrong place in the sky?
Do you mean the part where the lunar terrain is craggy and sharp and quite unlike the Moon we know?
Do you mean the part where stars are perfectly visible in scenes featuring spacecraft with white (or light-colored) hulls (even though said stars form into no recognizable constellations and indeed resemble no part of the night sky).
Do you mean the part where men on a craft traveling across the surface of the Moon move as if in 1G, or the part where men on the surface of the Moon aren't shown in any way being under lunar gravity (aka, the shots are cropped so you often can't even see their lower bodies), or perhaps the part where a pen in zero-G rotates around something other than its own COG?
Perhaps you mean the part where a spacecraft clearly reveals the presence of an atmosphere (in Kubrick's defense, the shot does take place in the depths of an artificial structure that probably does have non-zero contamination by exhausts and similar).