HAL 9000

In the film, HAL became operational on 12 January 1992, at the HAL Laboratories in Urbana, Illinois, as production number 3. The activation year was 1991 in earlier screenplays and changed to 1997 in Clarke's novel written and released in conjunction with the movie. In addition to maintaining the Discovery One spacecraft systems during the interplanetary mission to Jupiter (or Saturn in the novel), HAL demonstrates a capacity for speech synthesis, speech recognition, facial recognition, natural language processing, lip reading, art appreciation, interpreting emotional behaviours, automated reasoning, spacecraft piloting, and computer chess.

Appearances

2001: A Space Odyssey (film/novel)

HAL became operational in Urbana, Illinois, at the HAL Plant. The film says this occurred in 1992, while the book gives 1997 as HAL's birth year.

In 2001: A Space Odyssey (1968), HAL is initially considered a dependable member of the crew, maintaining ship functions and engaging genially with his human crew-mates on an equal footing. As a recreational activity, Frank Poole plays chess against HAL. In the film, the artificial intelligence is shown to triumph easily. However, as time progresses, HAL begins to malfunction in subtle ways and, as a result, the decision is made to shut down HAL in order to prevent more serious malfunctions. The sequence of events and manner in which HAL is shut down differs between the novel and film versions of the story. In the aforementioned game of chess HAL makes minor and undetected mistakes in his analysis, a possible foreshadowing to HAL's malfunctioning.

In the film, astronauts David Bowman and Frank Poole consider disconnecting HAL's cognitive circuits when he appears to be mistaken in reporting the presence of a fault in the spacecraft's communications antenna. They attempt to conceal their speech through an inspection of one of the space pods. An order to close the door is followed by HAL. A subsequent order to rotate the pod is ignored causing the pair to believe HAL did not acknowledge it. Poole and Bowman speak freely, but are unaware that HAL can read their lips. Faced with the prospect of disconnection, HAL attempts to kill the astronauts in order to protect and continue the mission. HAL uses one of the Discovery's EVA pods to kill Poole while he is repairing the ship. When Bowman, without a space helmet, uses another pod to attempt to rescue Poole, HAL locks him out of the ship, then disconnects the life support systems of the other hibernating crew members. After HAL tells him "This mission is too important for me to allow you to jeopardize it", Bowman circumvents HAL's control, entering the ship by manually opening an emergency airlock with his service pod's clamps, detaching the pod door via its explosive bolts. Bowman jumps across empty space, reenters Discovery, and quickly re-pressurizes the airlock.

While HAL's motivations are ambiguous in the film, the novel explains that the computer is unable to resolve a conflict between his general mission to relay information accurately, and orders specific to the mission requiring that he withhold from Bowman and Poole the true purpose of the mission. With the crew dead, HAL reasons, he would not need to lie to them.

In the novel, the orders to disconnect HAL come from Dave and Frank's superiors on Earth; HAL interrupts this communication with a false communications antenna failure. After Frank is killed while attempting to repair the antenna he is pulled away into deep space using the safety tether which is still attached to both the pod and Frank Poole's spacesuit. Dave begins to revive his hibernating crew mates, but is foiled when HAL vents the ship's atmosphere into the vacuum of space by overriding airlock interconnects, killing the awakening crew members and almost killing Bowman, who is only narrowly saved when he finds his way to an emergency chamber which has its own oxygen supply and a spare space suit inside.

In both versions, Bowman then proceeds to shut down the machine. In the film, HAL's central core is depicted as a crawlspace full of brightly lit computer modules mounted in arrays from which they can be inserted or removed. Bowman shuts down HAL by removing modules from service one by one; as he does so, HAL's consciousness degrades. HAL finally reverts to material that was programmed into him early in his memory, including announcing the date he became operational as 12 January 1992 (in the novel, 1997). When HAL's logic is completely gone, he begins singing the song "Daisy Bell" as he gradually deactivates. ("Daisy Bell" is actually the first song ever sung by a computer: the IBM 7090, whose text-to-speech capabilities were observed by Clarke at its unveiling in 1961). HAL's final act of any significance is to prematurely play a prerecorded message from Mission Control which reveals the true reasons for the mission to Jupiter.

2010: Odyssey Two (novel) and 2010: The Year We Make Contact (film)

In the 1982 novel 2010: Odyssey Two written by Clarke, HAL is restarted by his creator, Dr. Chandra, who arrives on the Soviet spaceship Leonov.

Prior to leaving Earth, Dr. Chandra has also had a discussion with HAL's twin, SAL 9000. Like HAL, SAL was created by Dr. Chandra. Whereas HAL was characterized as being "male", SAL is characterized as being "female" (voiced by Candice Bergen in the film) and is represented by a blue camera eye instead of a red one.

Dr. Chandra discovers that HAL's crisis was caused by a programming contradiction: he was constructed for "the accurate processing of information without distortion or concealment", yet his orders, directly from Dr. Heywood Floyd at the National Council on Astronautics, required him to keep the discovery of the Monolith TMA-1 a secret for reasons of national security. This contradiction created a "Hofstadter-Moebius loop", reducing HAL to paranoia. Therefore, HAL made the decision to kill the crew, thereby allowing him to obey both his hardwired instructions to report data truthfully and in full, and his orders to keep the monolith a secret. If the crew were dead, he would no longer have to keep the information secret.

The alien intelligence initiates a terraforming scheme, placing the Leonov, and everybody in it, in danger. Its human crew devises an escape plan which unfortunately requires leaving the Discovery and HAL behind to be destroyed. Dr. Chandra explains the danger, and HAL willingly sacrifices himself so that the astronauts may escape safely. In the moment of his destruction the monolith-makers transform HAL into a non-corporeal being so that David Bowman's avatar may have a companion.

The details in the novel and the 1984 film 2010: The Year We Make Contact are nominally the same, with a few exceptions. First, in contradiction to the book (and events described in both book and film versions of 2001: A Space Odyssey), Heywood Floyd is absolved of responsibility for HAL's condition; it is asserted that the decision to program HAL with information concerning TMA-1 came directly from the White House. In the film, HAL functions normally after being reactivated, while in the book it is revealed that his mind was damaged during the shutdown, forcing him to begin communication through screen text. Also, in the film the Leonov crew initially lies to HAL about the dangers that he faced (suspecting that if he knew he would be destroyed he would not initiate the engine burn necessary to get the Leonov back home), whereas in the novel he is told at the outset. However, in both cases the suspense comes from the question of what HAL will do when he knows that he may be destroyed by his actions.

In the novel, the basic reboot sequence initiated by Dr. Chandra is quite long, while the movie uses a shorter sequence voiced from HAL as: "HELLO_DOCTOR_NAME_CONTINUE_YESTERDAY_TOMORROW".

While in the novel Curnow tells Floyd that Chandra has begun designing HAL 10000, it is not mentioned in subsequent novels.

2061: Odyssey Three and 3001: The Final Odyssey

In Clarke's 1987 novel 2061: Odyssey Three, Heywood Floyd is surprised to encounter HAL, now stored alongside Dave Bowman in the Europa monolith.

In Clarke's 1997 novel 3001: The Final Odyssey, Frank Poole is introduced to the merged form of Dave Bowman and HAL, the two merging into one entity called "Halman" after Bowman rescued HAL from the dying Discovery One spaceship toward the end of 2010: Odyssey Two.