Cast of 2001: A Space Odyssey

Keir Dullea portrays Dr. David Bowman, the principal astronaut and mission commander aboard the Discovery One spacecraft.

Gary Lockwood plays Dr. Frank Poole, the second astronaut aboard the Discovery One, serving alongside Dr. Bowman.

William Sylvester takes on the role of Dr. Heywood Floyd, the National Council of Astronautics chairman involved in early lunar explorations.

Douglas Rain provides the calm yet eerie voice of HAL 9000, the Discovery One's artificial intelligence computer.

Daniel Richter embodies Moonwatcher, the prehistoric ape-man character who experiences a crucial evolutionary leap.

Leonard Rossiter plays Dr. Andrei Smyslov, a Russian scientist who discusses space travel concerns with Dr. Floyd.

Margaret Tyzack appears as Elena, a colleague of Dr. Floyd who greets him at the space station.

Robert Beatty plays Dr. Ralph Halvorsen, an American scientist in charge of the Clavius base on the moon.

Sean Sullivan portrays Dr. Roy Michaels, another scientist part of the Discovery One's mission briefings.

Frank Miller takes the role of the Mission Controller, who coordinates the Discovery One’s mission from Earth.

Ed Bishop is the Aries-1B Lunar Shuttle Captain, piloting Dr. Floyd to the lunar base.

Edwina Carroll plays the Aries-1B Stewardess, attending to passengers aboard the lunar shuttle.