This movie is mired in the politics of the time (mid 1980s) which means it does not age well. The 2001: A Space Odyssey movie, upon which this 2010 film is based, was free of politics and addressed timeless and universal themes - which means it's still fresh today. That cannot be said of this movie, watching which is like taking a time machine back to the era of mullets, track suits, and big hair.
Spoiler alert: Also, it's extremely implausible that the "two suns", the culminating event of the movie, is the panacea for the world's troubles that the film proposes. Having perpetual sunlight would probably wreak havoc with the world's ecosystem, which has evolved in a diurnal/nocturnal system.
Helen Mirren is also unusually ridiculous in her role as the hard-boiled Russian mission leader and pilot - from her execrable Russian accent to her absurd frizzy permed hair, she reeks of "I'm just here as a mid-1980s feminist icon with no other dramatic value!"
A particularly risible scene is when the Russian vessel does some kind of dangerous slingshot maneuver around Jupiter and Roy Scheider cuddles up with a wee cutey Russian crew member for comfort, exchanging a quick kiss afterwards - a scene that comes out of nowhere in the plot and goes nowhere the rest of the movie. Why?
And a monstrous red herring in the film is the American computer expert with a serious (and laughable) emotional crush on HAL 9000. The character's bizarre attachment to the computer leads you to think that he will scuttle the whole mission to save HAL from destruction, but he doesn't in the end and HAL is consigned to space oblivion.