No, they're (zero gravity sequences in '2001') not. They're really not. They're ingeniously shot but they do not pass muster under close examination as true zero gravity footage.
Anybody who thinks the reduced or zero-g sequences in '2001' are accurate hasn't seen the movie recently (or ever). While a breakthrough for its time, it was released in the spring of 1968, half a year before the first manned Apollo flight. No one had ever seen astronauts in a weightless environment big enough to actually let them move, and it would be five more years before astronauts could move around in a volume even remotely comparable to the huge spaceships we see in '2001'.
Kubrick, Clarke and their audiences had no real idea how weightless people would actually look, behave and adapt. So besides the obvious physics errors like the pen and the food tray, we get absurdities like the flight attendant in velcro shoes walking tediously down the aisle. A
real astronaut would have just pushed off, sailed to the front of the cabin in a few seconds and turned a somersault to go through the door to the flight deck.
We see many similar scenes in the
Discovery. Only the centrifuge is in artificial gravity. The command module (where Frank and Dave monitor each others' EVAs) and the pod bay (where they begin their EVAs, analyze the AE-35 unit, and discuss Hal) are in zero-G, just like Hal's "brain room". But neither actor moves as we now know every real astronaut moves in a roomy weightless area, especially when they've been in space for a long time. It's that same tedious walking on velcro shoes.
Obviously this was done to simplify filming, but that just raises the question why, if the Apollo footage was faked on earth, those doing the faking made it so much harder for themselves with so many gratuitous, lengthy scenes of people and objects in zero- and reduced gravity. Any one of these sequences could have failed the test of time and eventually tripped them up --
if they hadn't been real.
Ron Howard knew his 1994 audience for 'Apollo 13' was a lot more sophisticated than the 1968 audience for '2001', so he went to great expense to use real zero gravity for at least some of his space sequences, hiding the short durations possible in an airplane with frequent edits. It wouldn't have worked otherwise.
