Other mistake: There is something drastically wrong with the design of the spherical 'Aries' moon shuttle. Some seats and many fixtures are 'upside down' relative to the up-down orientation of the shuttle itself, and we see loose food trays and equipment about the place as if this is routine. But - the shuttle is designed to land on the moon. What happens then? The moon has gravity, remember? There are going to be quite a few very disgruntled people dangling upside down like spiders, and there will be loose gear (and perhaps a stewardess or two) bouncing about all over the place. It is not a matter of stowing loose gear or lying flat on landing - some parts of the shuttle are upside down relative to others, which is why the stewardess has to do that famous 180 degree upside down walk. Whichever way you look at it the shuttle is going to encounter serious problems when it reaches a gravity well, which will occur whenever the engines are fired up, never mind landing on the moon.
Other mistake: When Dave is deactivating HAL, he unlocks memory blocks one by one by turning a key for every one of them. When he's done the first five memory blocks, from number 6 to 2, he changes the key from right to left hand, and jumps to the logic terminal blocks, unlocking number 5 of those. However, number 1 of the memory blocks slides out. (01:48:20)
Other mistake: When Frank does his first EVA he presses a button to darken his visor, but the button is marked "TEST ALARM" (visible on Blu-Ray version).
Other mistake: When Dr. Floyd's ship is descending to Clavius, the Earth is out of the window, rising. The Earth should have held position because of its distance.
Suggested correction: The shuttle lands "on its back" with legs extending beyond the engines. As in most traditional sci-fi, and ALL actual, space flights to date, the launch (and landing) orientation for humans is to be on one's back. This minimizes blood being sucked down to your feet if you were sitting upright at launch - you could pass out. So we see this when the shuttle lands on the moon - the cockpit (red window) faces up (pilots on their backs, facing out the window). When we presume that the passenger cabin was 180 degrees spun around from the cockpit seating, they're still on their backs. Any loose objects would have been stowed before landing - the airlines don't lock down your bags, newspapers and coffee cups, right? They're loose in the cabin during flight, but put away on takeoff and landing.
Airliners do not fly upside down. The Orion shuttle cannot possibly operate the way it does if it lands in a gravity environment - some rooms are upside down relative to others - why else would the stewardess do the 180 degree vertical walk? It is an idiotic design flaw, and the posting is 100% correct.
The Aries passengers sit and stand with their feet down towards the moon. The pilots sit with their back down to the moon, as conventional astronauts do on Earth. But the attendant's 180-degree walk is completely wrong to the orientation of the shuttle's interior: it should have been only 90° if you look at the Aries exterior. One assumes that Kubrick preferred a longer, more cinematic shot, over a technically accurate shot. But nobody was upside-down to the moon.