Dimension X

Dimension X was an NBC radio programme broadcast from 8 April 1950 to 29 September 1951. The first 13 episodes were broadcast live, and the remainder were pre-recorded.

Dimension X was not the first adult science fiction series on radio, but the acquisition of previously published stories immediately gave it a strong standing with the science fiction community, as did the choice of well established, respected writers in the field such as Isaac Asimov, Ray Bradbury and Robert A. Heinlein. Other notable writers whose stories were adapted for the series include Robert Bloch, Fredric Brown, Murray Leinster, H. Beam Piper, Frank M. Robinson, Clifford D. Simak, William Tenn, Jack Vance, Kurt Vonnegut, Jack Williamson and Donald A. Wollheim.

Producers Ernest Kinoy and George Lefferts adapted most of the stories and also provided original scripts.
Episode 31: Universe

Humanity's descendants aboard a space Ark are divided into two factions — the lower decks occupied by humans, and the upper by mutants. One man dares probe the upper levels and his quest leads him to question not only his society's prejudices, but the ultimate truth of what might lie beyond the Ship.

​First broadcast: 26 November 1950.
Original Story by Robert A.Heinlein.
​Cast: Mason Adams, Peter Capell, Abby Lewis, Raymond Edward Johnson, Ross Martin, Robert Dryden, Matt Crowley.

Episode 32: The Green Hills of Earth

Classic story of a space engineer who suffers a tragic accident and ends up tramping about the Solar System singing about the life of spacers and dreaming of returning to Earth once more before he dies. Repeat of episode 10. Includes President Truman's 1950 Christmas message to the nation.

First broadcast: 24 December 1950.
Original Story by Robert A. Heinlein.
​Cast: Ken Williams, Tom Glazer (singing), Karl Weber, Bill Griffis, Matt Crowley. Cameron Prud'homme,  Bill Zuckert, Bob Dryden, Staats Cotsworth.

Episode 33: Mars Is Heaven

The first astronauts to land on Mars discover... Earth — a planet where their long-dead loved ones are waiting for them in a small Midwest town just like home. Part of Ray Bradbury's Martian Chronicles series. Repeat of Episode 14.

First broadcast: 7 January 1951.
Original Story by Ray Bradbury.
​Cast: Wendell Holmes, Peter Capell, Joseph Julian, Bill Zuckert, Bill Lipton, Bill Griffis, Ethel Everette, Charme Allen, Cameron Prud'homme.

Episode 34: The Martian Death March

On a Mars conquered by Earthmen, the few remaining spider-like Martians escape from their reservation and embark on a desperate trek across the deserts to their mountain homelands, lead by a human religious fanatic.

​First broadcast: 14 January 1951.
Original Story by Ernest Kinoy.
​Cast: Butch Cavell, Cameron Prud'homme, James Monks, Ralph Bell, Jim Stevens, Bill Zuckert, Roger De Koven, Lawson Zerbe, Nelson Olmstead.

Episode 35: The Last Objective

After nuclear devastation and fallout has rendered the Earth's surface virtually uninhabitable, Man continues to pursue war underground in tunneling 'warships'.

​First broadcast: 3 June 1951.
Original Story by Paul Carter.
​Cast: Lawson Zerbe, Ralph Bell, Wendell Holmes, Jackie Grimes, Joseph Julian,  Bill Zuckert, Cameron Prud'homme, Staats Cotsworth.

Episode 36: Nightmare

A statistician begins to suspect that machines worldwide are uniting to overthrow their human masters.

​First broadcast: 10 June 1951.
Original Story by Stephen Vincent Benét.
​Cast: John Gibson, Rita Lynn, Joseph Julian, Edwin Jerome, Joe DiSantis, Gregory Morton, John McGovern.

Episode 37: Pebble In The Sky

A radioactive and decrepit Earth prepares in secret for a deadly gambit to reclaim its prodigal colonies and rebuild its galactic empire.

​First broadcast: 17 June 1951.
Original Story by Isaac Asimov.
​Cast: Santos Ortega, Susan Douglas, Edwin Jerome, Leon Janney.

Episode 38: Child's Play

A mild-mannered lawyer accidentally receives a package in the mail containing a cloning machine from the future, with which he sets about making a duplicate capable of turning his life around.
​
​First broadcast: 24 June 1951.
Original Story by William Tenn.
​Cast: Leon Janney, Karl Weber, Patsy Campbell, Ian Martin, Adelaide Klein.

Episode 39: Time And Time Again

A soldier dying on a battlefield of the future suddenly finds himself transported back to his own childhood.

​First broadcast: 12 July 1951.
Original Story by H. Beam Piper.
​Cast: David Anderson, Joseph Curtain, Peter Capell, Joe DiSantis.

Episode 40: Dwellers In Silence

Colonists from Mars return to Earth generations after the Atomic War and discover a few survivors — a family with some very odd peculiarities about them. Part of Ray Bradbury's Martian Chronicles series.

​First broadcast: 19 July 1951.
Original Story by Ray Bradbury.
​Cast: Peter Capell, Bill Griffis, Gertrude Warner, John McGovern.