This episode was filmed at the same time as The AB Chrysalis (1976), which was why Nick Tate doesn't appear, and both Martin Landau and Catherine Schell (who only has two full lines) appear sparingly.
Koenig's co-pilot was written to be Bill Fraser, but budget restrictions forced them to use an unknown actor instead of John Hug, (but still referring to the unknown as "Bill").
While filming Osgood's dream sequence of Alpha being engulfed in flames, the fire used on the set got out of control and the fire brigade had to be called in. Production was shut down for two days while repairs were made.
This was Zienia Merton's first appearance since One Moment of Humanity (1976) (which had been Season Two's third episode in production order).
The original script had the mechanical heart modeled after Victor Bergman's, but his name (mentioned in dialogue) was eventually omitted; most likely the decision coming from producer/script editor Fred Freiberger (who was not a fan of any of the characters from the first series apart from the two leads).