"Collision Course" is the thirteenth episode of the first series of Space: 1999. The screenplay was written by Anthony Terpiloff; the director was Ray Austin. The final shooting script is dated 13 August 1974. Live-action filming took place Tuesday 27 August 1974 through Tuesday 10 September 1974. Story A large asteroid hurtles through space on collision course with the Moon. As Moonbase Alpha is located within the impact area, the staff formulates a plan to avert disaster. To guarantee the asteroid's destruction, twelve nuclear charges will be planted at strategic locations. The Eagle task force delivers eleven charges. However, due to a malfunction of Eagle One, Alan Carter fails to deliver the twelfth charge within the original timeline. The charges are detonated as first Carter's Eagle, then the Moon, are engulfed in a debris cloud billowing outwards from the volatilised asteroid. Radiation interference blots out communications and scanners. The staff compiles damage reports and monitors the functioning of the protective radiation screens. John Koenig repeatedly tries to contact Eagle One, refusing to believe Carter is dead. When discovering that signals transmitted on the interstellar frequency can penetrate the radiation field, he reckons that three-way contact could be established between Moonbase, a rescue Eagle equipped with a more powerful transmitter, and Carter. Paul Morrow voices the danger of the pilots' potential exposure to radiation. Koenig disagrees, feeling the Eagles' radiation screens are sufficient. Victor Bergman stresses there is an unknown class of radiation present in the cloud against which they may have no defence. The Commander disregards his advice and lifts-off in Rescue Eagle Four, with Morrow as co-pilot, flying blind through the plasma cloud, sending out hails. Though unconscious and unable to hear Morrow's signal, Carter stirs at the whisper of a woman's voice. She instructs him to answer his friend, which he does while unconscious. When trying to determine Carter's position, the same disembodied voice whispers coordinates in Koenig's ear. Watched by a puzzled Morrow, the Commander programmes a course without computer assistance. They soon find Eagle One drifting beyond the boundary of the cloud. They move in and dock, Carter's mysterious benefactor urging him to perform all necessary actions on his end. She then takes her leave, assuring him she is a friend. When Koenig boards the ship, he finds Carter insensate. He is stunned by what he sees through the forward ports, a huge planet that has