Floyd: The protagonist, Floyd must embark on an odyssey to Jupiter with American colleagues aboard a Soviet ship, the Leonov, to revive Discovery. Dr. Walter Curnow: gregarious American engineer and expert on Discovery's systems. Dr. Sivasubramanian Chandrasegarampillai, or "Dr. Chandra": HAL's inventor. Quiet and reserved, Dr. Chandra, who is Indian, is the third member of the American team, charged with re-activating HAL. For the 1984 film, the character was changed to a white American played by Bob Balaban. Captain Tatiana "Tanya" Orlova: Soviet captain of the Leonov. The character's last name in the film was changed to Kirbuk and was played by British actress Helen Mirren. Dr. Vasili Orlov: the Leonov's chief scientist, and husband of Orlova. Dr. Maxim (Max) Brailovsky: Spacewalker and Curnow's Soviet counterpart. He and Curnow are both bisexual and enjoy a romantic relationship during the mission, though Max eventually becomes engaged to Zenia Marchenko. Surgeon Commander Katerina Rudenko: The Leonov's matronly medical doctor. In the film, this character is recast as a man. Dr. Alexander "Sasha" Kovalev: Communications officer of the Leonov, Sasha states basic science information at certain points. Dr. Nikolai Ternovsky: The computational expert for the Leonov crew, Ternovsky works with Dr. Chandra to reactivate HAL upon the Discovery rendezvous. Zenia Marchenko: an understudy for Dr. Irina Yakunina, ship's nutritionist. In the book, Marchenko shelters with Floyd while the Leonov executes a dangerous and dramatic maneuver. The film's equivalent character, who likewise shelters with Floyd, is there named as Irina Yakunina, the same namesake as the book's replaced character, who in the book does not actually join the Leonov's voyage, due to a hang gliding accident. HAL 9000: the Discovery's on board ship's computer, HAL is held suspect by most other characters for having caused the deaths of the Discovery's crew except Bowman, despite the explanation that HAL was given conflicting orders regarding secrecy and deception, which HAL is manifestly not designed to carry out. Minor characters The Floyd family: Floyd is described as having had two families. Floyd's deceased first wife, Marion, is said to have borne him two daughters. At the time of the novel's events, Floyd is living with his second wife, Caroline, and their son Christopher, a toddler. A male dolphin named Scarback, together with its mate, routinely visit the Floyd household, and communicates with Christopher in a language dubbed Dolphin. The Bowman family: In a series of flashbacks and