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