The Pathfinders in Space trilogy was a series of three distinctly-named ABC children's television programmes — plus a prequel — that ran from 1960-1. The plots focused on exploration of the Moon, Mars and Venus. They were produced by Sydney Newman and written by Malcolm Hulke and Eric Paice. There was also a prequel series (starring Michael Craze) that has been lost. The series is considered one of the three central influences on Doctor Who, the others being Journey into Space  and Quatermass.
Target Luna (Prequel)
According to "The Pathfinders in Space Series Guide" by Andrew Pixley, this serial followed the three children of Prof. Norman Wedgewood (David Markham), Geoffrey (Michael Craze), Valerie (Sylvia Davies) and Jimmy (Michael Hammond), after their arrival on the Buchan Island Rocket Research Station. When Flight-Lieutenant Williams (William Ingram) becomes ill just before the first mission to orbit the Moon is about to blast off, Jimmy, the youngest of the three children, sneaks into the rocket with his pet hamster, Hamlet, and accidentally launches himself into space. Once in orbit, Jimmy must face several challenges, including the frigid cold of outer-space, loss of communication with the ground crew, cosmic particles and re-entry. In the end, Jimmy survives and returns to Earth. These events are covered by a reporter named Henderson (Frank Finlay), who would become one of the leading characters in subsequent serials. These events are recounted and briefly summarised in episode one of Pathfinders in Space.
Michael Craze was 17 years old when he played the part of Geoffrey.A publicity photo of him and his co-stars can be found at http://www.televisionheaven.co.uk/targetluna.jpg All three children would be recast for Pathfinders in Space. Six years after Target Luna, Craze was cast as Able Seaman Ben Jackson in TV:The War Machines.
Pathfinders in Space
Pathfinders to Mars
Henderson (Gerald Flood) fills in for an injured Prof. Wedgewood on an imminent rocket trip to the Moon. He recruits the help of Geoffrey Wedgewood (Stewart Guidotti) as radio operator as well as his niece, Margaret (Hester Cameron). Already on the mission is Prof. Mary Meadows (Pamela Barney); the last crew member is a Prof. Hawkins (Bernard Horsfall), who is arriving from Australia just before take-off. However, Hawkins in intercepted at the airport by a man (George Coulouris) who assumes his identity and boards the rocket.
The design of the interior of the rocket may have had a partial influence on the design of the TARDIS walls. Some of the bulkheads are decorated with circles organised in columns.
Pathfinders to Venus
to be added
While there were no outright sequels to this trilogy, some of the actors returned in the ABC productions Plateau Of Fear, City Beneath The Sea and Secret Beneath The Sea.