Trivia: There were a lot of changes to the show throughout the second season. Not only was Virgil "re-cast" with both a new head and voice actor (Jeremy Wilkin), but smaller, more lifelike puppet hands were crafted on the marionettes, and the inside of Tracy Island and the Thunderbird crafts were completely redone.
Trivia: The launch of the Sun Probe at the start of the episode is the same event that was seen in the flashback at the start of "Sun Probe". The events of that episode take place one week after the launch, so this episode takes place immediately before. Indeed, this episode and "Sun Probe" can be viewed as the series' only two-part story, although they have never been broadcast as consecutive episodes.