Closed Planet by John Hynam

In the New Age interplanetary travel has become an everyday occurrence. and Time rather than Distance now sets the only limit on man's exploration of the universe.

It seems, however, that Outer Space, like our own familiar world, also has secrets to hide, frontiers to guard, "security" zones to protect. Such a place is the "closed" planet, and only dire necessity may excuse the deliberate infringement of its astral neutrality by visitors from Earth.

Music and special effects: BBC Radiophonic Workshop
Producer: Archie Campbell
Crew of Spaceship Dromio: Captain Karl Hunsecker, in command: John Glen
Crew of Spaceship Dromio: Commander Almquist, second in command: Frank Partington
Crew of Spaceship Dromio: Lt. Commander Chavasse, First Officer: Andre Maranne

Crew of Spaceship Dromio: Lt. Commander Anderson, Records Officer: Rolf Lefebvre
Crew of Spaceship Dromio: Senior Lieut. Han de Witt, Astrogation Officer: George Hagan
Crew of Spaceship Dromio: Lieut Leela de Witt, Medical Officer: Bandana Das Gupta
Crew of Spaceship Dromio: Lieut. Dave Carey, Assistant Astrogation Officer: Andrew Irvine
Crew of Spaceship Dromio: Chief Artificer Dan Kisonga: Lionel Ngakane
Crew of Spaceship Dromio: CPO Jennings: Anthony Hall
Crew of Spaceship Dromio: Radio Operator Karasawa: Eric Young
Crew of Spaceship Dromio: Nurse Longmer: Dorit Welles
Dranethans: Serema-Da, an elderly councillor: Peter Pratt
Dranethans: Akram-Me, a senior police officer: Arthur Gomez
Dranethans: Imre-Ge, a young news reporter: Peter Bartlett
Crew, radio-operators, Dranethan Guards: Members of the BBC Drama Repertory Company