Flood as Conway Henderson George Coulouris as Harcourt Brown (credited as 'The Imposter' in The Imposter) Stewart Guidotti as Geoffrey Wedgwood Pamela Barney as Professor Mary Meadows Hester Cameron as Margret Henderson Hugh Evans as Ian Murray Astor Sklair as John Field Bernard Horsfall as Professor Hawkins Peter Williams as Professor Norman Wedgwood (Episode 1 The Imposter only) Pathfinders to Venus Guy Verney continued as director for episodes 1–5 and 7. Episodes 6 and 8 were directed by Reginald Collin. The main cast themselves remained from the previous serial, with the additions of Captain Wilson and Kiki. Gerald Flood as Conway Henderson George Coulouris as Harcourt Brown Stewart Guidotti as Geoffrey Wedgwood Pamela Barney as Professor Mary Meadows Hester Cameron as Margret Henderson Graydon Gould as Captain Wilson Hugh Evans as Ian Murray Astor Sklair as John Field Brigid Skemp as Kiki (credited as Venusian Child) Bob Bryan as The Venusian Robert James as Colonel Korolyov Production Sydney Newman wanted to develop a children's adventure serial, which could educate its audience about science and the developing Space Race. Malcolm Hulke and Eric Paice wrote all four serials. Target Luna was directed by Adrian Brown. The three Pathfinders serials were directed by Guy Verney with two chapters directed by Reginald Collins. Pathfinders to Venus included scenes of animated Dinosaurs from the Czech film Journey to the Beginning of Time. Midway through Pathfinders to Mars at the last minute, it was decided to have the last three episodes filmed live owing to timing reasons. Reception and influence Target Luna and the three sequels gained high audience ratings at the time. One episode was broadcast on Christmas Day 1960 and the production team claimed it had the second highest audience of the day after the Queen's Speech. Professor Wedgwood and his experimental rocket group appears to be a direct reference to the character and success of Professor Bernard Quatermass on the BBC. The seventh episode of Pathfinders to Venus (The Valley of Monsters) was used in an academic study of children's attitudes to television viewing. The experiments included showing several on-screen mistakes which were explained at the end of the episode by onscreen-rolling captions: The mistakes in this episode which you may have noticed are not accidental. They are part of a research project into children's perceptions which the Department of Education of Cambridge University is carrying out in co-operation with the Drama