Dean Jagger ( On the Threshold of Space
)
Guy Madison ( On the Threshold of Space
)
Martin Milner ( On the Threshold of Space
)
Warren Stevens ( On the Threshold of Space
)
Walter Coy ( On the Threshold of Space
)
John Hodiak ( On the Threshold of Space
)
Ken Clark ( On the Threshold of Space
)
Barry Coe ( On the Threshold of Space
)
Virginia Leith ( On the Threshold of Space
)
Donald Murphy ( On the Threshold of Space
)
King Calder ( On the Threshold of Space
)
Helen Bennett ( On the Threshold of Space
)
David Armstrong ( On the Threshold of Space
)
Dan C. Ogle ( On the Threshold of Space
)