Guest Stars Derek Ware as Unit Sergeant Tony Harwood as Flynn Neville Simons as Michaels Peter Noel Cook as Alien Space Captain Steve Peters as Astronaut Steve Peters as Lefee Neville Simons as Astronaut Ronald Allen as Ralph Cornish Dallas Cavell as Quinlan James Haswell as Corporal Champion Ric Felgate as Van Lyden Juan Moreno as Dobson Michael Wisher as John Wakefield John Lord as Masters Cheryl Molineaux as Miss Rutherford William Dysart as Reegan Robert Cawdron as Taltalian Roy Scammell as Technician Max Faulkner as Unit Soldier James Clayton as Private Parker Carl Conway as Control Room Assistant Joanna Ross as Control Room Assistant Bernard Martin as Control Room Assistant Geoffrey Beevers as Private Johnson Ric Felgate as Astronaut Robert Robertson as Collinson Derek Ware as Astronaut Gordon Sterne as Heldorf Ray Armstrong as Grey Peter Halliday as Alien Voices Cyril Shaps as Lennox John Abineri as General Carrington
