2010
The film is set nine years after the mysterious failure of the Discovery One's mission to Jupiter, depicted in 2001: A Space Odyssey, in which four astronauts (apparently in one case) died and another one disappeared mysteriously into the large, alien-made Black Monolith orbiting Jupiter. Dr. Heywood Floyd (Roy Scheider, taking over from the actor William Sylvester, who played this role in "2001") - who had been the Director of the so-called "National Council on Astronautics" (NCA) during the Discovery One's mission - has been made the scapegoat, and has since left the NCA to become the Chancellor of the University of Hawaii.
Amid growing friction between the United States and the Soviet Union, both nations are preparing to send missions to Jupiter to determine what happened to the Discovery One's mission. After delay's in the American plans, the Soviets suggest a joint mission to Jupiter: their spaceship, the Alexi Leonov will be ready one year before the new American spaceship, the Discovery 2 will be completed, but they need American astronauts to help investigate the problems with the HAL 9000's on-board supercomputer system. Also, since the Discovery One is an American spaceship, she remains American territory wherever she has gone (in this case, into Jovian orbit), and she may not be visited, investigated, or moved without American permission. The United States Government will not grant this permission unless several American astronauts are taken along to participate, and to supervise the Soviets. The American government somewhat reluctantly agrees to the joint mission, since recent space-tracking data shows that the Discovery One is destined to crash into the Jovian moon Io within a few years because its orbit is being gradually perturbed (shifted) in that direction.
Dr. Floyd feels responsible for the failure of the Discovery One's mission and the apparent death of all five of its astronauts, and thus he volunteers for the mission himself to lend his expertise in spaceflight. Floyd recruits two well-known experts on the Discovery One and her computer system: Dr. Walter Curnow (John Lithgow), an astronautical engineer and one of the original designers and builders of the Discovery One, and Dr. Chandra (Bob Balaban), the computer scientist and engineer who created the extremely-advanced HAL 9000 series of artificial-intelligence supercomputers. They both agree to go on the flight of the Alexi Leonov.
The mission of the three Americans, along with the Soviets, is threefold: A). To find the reason for the Discovery One mission's failure, B). To investigate the Black Monolith that is in orbit around Jupiter, C). To find the answer for David Bowman's disappearance. They suspect that much of this information is locked away in the abandoned Discovery One spaceship and her on-board HAL 9000 computer.
Upon the Alexi Leonov's arrival in the Jovian system, Dr. Floyd is awakened from his long, rsource-conserving hibernation two days early by the Soviets in the crew, because they have detected the chemical signatures of life on one of the Jovian moons, Europa. Together, they send an unmanned science probe to explore the icy surface of Europa. The probe's instruments spot something that is suggestive of life, but the the probe is inexplicably destroyed in a burst of electromagnetic radiation before any close-up photos can be taken. The Soviets themselves blame this on electrostatic build-up, but Dr. Floyd suspects that it is a warning from someone or something — to keep away from Europa.
Next, the Discovery One is found abandoned but undamaged in its orbit around Jupiter. After space walking over to the American spaceship from the Alexi Leonov, Engineer Curnow slowly reactivates its on-board systems, step-by-step, and then the two spaceships rendezvous with Io. Dr. Chandra then restarts the HAL 9000 computer ("HAL"), but he only learns that HAL had been deactivated before the Monolith had been found. That huge Black Monolith is next re-discovered in the Lagrange point located between Jupiter and Io. The Soviet Commander Kirbuk (Helen Mirren) sends the cosmonaut Max Brailovsky (Elya Baskin), over to it for a closer look via an EVA pod. However, a large burst of power from the Monolith destroys Max's EVA pod, and next it heads into outer space, perhaps towards the Earth.
A series of scenes follows that show the explorations and visits by Dave Bowman (the actor Keir Dullea), who has been transformed by super-intelligent aliens into an incorporeal being. The tramsformed Dave Bowman, containing his mind and spirt, travels to the Earth, where he makes contact two with significant people from his past: first he appears on his widow Betty Fernandez's television screen and has a conversation with her, saying his final good-byes. (She is played by the actress Mary Jo Deschanel). Next he visits his terminally-ill and senile mother in a nursing home. Unable to talk with here, he lovingly combs her hair, much to her delight, just as he had done during his boyhood in Florida. She is very shortly found dead in her bed.
After many tests on the HAL computer, Chandra discovers why HAL had malfunctioned: the National Security Council (NSC) had decided that neither of the awake astronauts, Dave Bowman nor Frank Poole, would be informed of the true objective of the Discovery One's mission to Jupiter until arrival in Jovian orbit there. HAL had been told the truth: it was very strongly suspected that the Black Monolith dug up on the Moon in 2001 was an alien artifact, and in fact on that had been deliberately buried to wait for intelligent life from the Earth to come and dig it up. It had beamed a deliberate radio message towards Jupiter for some reason, and the NSC wanted to investigate the Jovian system to find out what extraterrestrial things or beings were there. However, HAL had been told not to tell Bowman or Poole about this until they reached Jupiter. The other three astronauts on board the Discovery One knew about the alien presence, but they had been placed about the spaceship while in hibernation already. Bowman and Poole would not find out until their arrival at Jupiter, when they would be filled in by the other three astronauts and by HAL.
The HAL computer became "paranoid" because the order to keep quiet was in direct conflict with HAL's basic design: the accurate processing and distribution of information without concealment or distortion. (This is a piece of science fiction story plotting on the part of Dr. Clarke, and it has nothing to do with the way that real computers work or ever will work.) Dr. Floyd becomes disgusted with what the NSC did, and he denies any knowledge of the secret directive. (After all, Floyd worked for completely-separate organization, the "National Council on Astronautics.)
Meanwhile, political tensions between the United States and the Soviet Union, particularly regarding the country of Nicaragua, have escalated to "technically a state of war", with warships at sea firing on one another. Dr. Floyd, Engineer Curnow, and Dr. Chandra are all ordered by their Government to leave the Alexi Leonov and to move into the Discovery One, which is still a spaceship that belongs to the United States. (Just as any warship always belongs to its home country, even if it is sunk to the bottom of the ocean.)
On board the Discovery One, soon Dave Bowman appears to Floyd, warning him that they must leave Jupiter within two days because "Something wonderful" will happen. The huge Black Monolith suddenly disappears, and a black, growing spot appears on the Jovian surface. Telescopic observations reveal that the Great Black Spot is in fact a vast population of Black Monoliths, increasing in number at an exponential rate, shrinking Jupiter's volume, increasing its density, and modifying the chemical properties of its atmosphere with each passing minute. Since neither ship can reach the Earth with an early departure, the two crews work together to use the Discovery One as a booster rocket for the Alexi Leonov. HAL is not told that the Discovery One will be left stranded in space, and probably destroyed, and Chandra worries that this may cause its malfunctions to return. During the countdown Dr. Chandra tells HAL the whole truth, and much to everyone's collective relief, HAL understands that it must sacrifice itself for the good of the human beings on board the Alexi Leonov.
The Alexi Leonov makes a hasty retreat from its orbit around Jupiter just in time to witness the swarm of huge Monoliths engulf Jupiter. The collection of Monoliths eventually increases Jupiter's density to the point that the planet achieves the high temperatures and pressures necessary for nuclear fusion, thus Jupiter becomes a small star. A huge wave of hot plasma erupts from the forming star, which incinerates the Discovery One, and threatens the Alexi Leonov.
As the Alexi Leonov exits its Jovian orbit, HAL is commanded by the mysterious extraterrestrial intelligences to repeatedly broadcast this message toward the Earth:
The film concludes with images of two Suns in the sky of the Earth, and Dr. Floyd, in a voice-over, explains that this miraculous occurrence has inspired both the American and the Soviet leaders to end their stance of war. On Europa, this moon gradually transforms over millennea from an icy wasteland to a humid jungle covered with plant life (and likely animal life as well, given the primordial sounds emanating from the trees). As the camera pans across the jungle, it settles upon a lagoon... and a lone Black Monolith standing upright, waiting for intelligent life forms to evolve.
